clinical epidemiology complete

7/15/2019 Clinical Epidemiology Complete

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Chapter 8 and 3 Q9

Question 14 out of 4 points

Pap smears and mammograms are examples of

Answer

Selected Answer: b.

secondary prevention

Correct Answer: b.


• Question 24 out of 4 points

All the following activities are considered secondary prevention except:Answer

Selected Answer: b.

Construction of a pair of dentures

Correct Answer: b.



All activities in medicine could be defined as preventionAnswer

Selected Answer:

a.True

Correct Answer:a.

True


A comparison of clinically diagnosed versus autopsy-confirmed myocardial

infarctions was performed among 1000 consecutive deceased patients, asshown in the table

Clinical diagnosis

Autopsy findings

Total

MI No MI

MI 160 80 240

No MI 40 720 760



Total 200 800 1,000

From these data, the negative predictive value of the clinical diagnosis wasclosest to

Answer

Selected Answer:d.

95%

Correct Answer:d.

95%


A bias occurs because the proportion of slow-growing lesions diagnosedduring screening is greater than the proportion of those diagnosed during usualmedical care is calledAnswer

Selected Answer: b.

length-time bias

Correct Answer: b.

length-time bias

• Question 6

0 out of 4 points

The incidence of breast cancer in 20-year-old women isAnswer

Selected Answer:a.

1 in 10,000

Correct Answer: b.

1 in 100,000


Among 100 patients with Alzheimer’s disease, 15 subjects score within thenormal range on a battery of tests of cognitive performance. Select the most

appropriate measure from the following lettered options

Answer

Selected Answer:f.

specificity



Correct Answer:d.

sensitivity


Lack of compliance in the screened group results in an overestimation of thescreening effect. Answer

Selected Answer:True

Correct Answer:False


As the true positive of a screening test increases, which of the followingoccurs?Answer

Selected Answer:a.

specificity and positive predictive value increase

Correct Answer:d.

sensitivity and positive predictive value increase


Federal laws require rigorous evidence of efficacy for behavioral counselingmethods before these methods are approved for use.Answer




A prevention program that is oriented to the most experienced drug user would

be referred to as

Answer

Selected Answer:c.

tertiary

Correct Answer:c.

tertiary


The incidence method can be used to calculate sensitivity for cancer screening

tests



Answer

Selected Answer:a.

True

Correct Answer:a.

True


Hand washing to stop bacteria and viruses from spreading is classified asAnswer

Selected Answer:a.

primary prevention

Correct Answer:a.

primary prevention




Clinical diagnosis

Autopsy findings

Total

MI No MI

MI 160 80 240

No MI 40 720 760

Total 200 800 1,000

From these data, the positive predictive value of the clinical diagnosis was

closest to

Answer

Selected Answer:e.

95%

Correct Answer:a.

67%


The first time that screening is carried out is called an incidence screen.Answer



Selected Answer:a.

True

Correct Answer: b.

False


The percentage of false-positive in screening mammograms is approximatelyAnswer

Selected Answer:a.

1%

Correct Answer: b.

10%


For many diseases, there is a critical point in time beyond which therapy is less

effective. For most cancers, the critical point occurs when the primary tumor metastasizes. When must the critical point occur for screening to be effective?

Answer

Selected

Answer:a.

After the disease is detectable but before it producessymptoms.

Correct Answer:a.

After the disease is detectable but before it produces

symptoms.


Helping patients to exercise appropriately is an exaple of Answer

Selected Answer:a.

primary prevention

Correct Answer:

a. primary prevention


Which of the following best defines the "yield" of a screening test?Answer

Selecteda.



Answer: How much of a disease the screening test can detect in the

screening process.

Correct

Answer:a.

How much of a disease the screening test can detect in the

screening process.


Screening for very rare disease is beneficial to very few peopleAnswer

Selected Answer:a.

True

Correct Answer:a.

True


Ascertainment bias in determining the cause of death does not affect the

estimation of thescreening effect. Answer

Selected Answer:False



Which of the following is not a primary requirement for conducting screeningfor disease controlAnswer

Selected Answer:d.

The disease should be serious

Correct Answer:c.

The government should fund the program


The use of drugs to prevent disease isAnswer

Selected Answer:e.

all of the above

Correct Answer:c.

chemoprevention




Screening tests are part of Answer

Selected Answer: b.


Correct Answer:d.

a and b


When prevalence is low, the negative predictive value of a screening test is

likely to be high.Answer

Selected Answer:

b.False

Correct Answer:a.

True


Sensitivity, specificity, predictive value, and cost are independent of eachother.Answer




Labeling effects of screening tests are sometimes unpredictable.Answer


Correct Answer:True


Which is the best way to avoid biases when evaluating the efficacy of ascreening test or treatment in a clinical trial?Answer

Selected Answer: b.

Randomization



Correct Answer: b.

Randomization


Screening for disease involve which type(s) of prevention?Answer

Selected Answer:d.

all of the above

Correct Answer: b.

secondary


Compliant patients tend to have better prognoses regardless of screening.

Answer

Selected Answer:a.

True

Correct Answer:a.

True

!

Question!1!!

4!out!of!4!points!

! !

!

A!good!screening!test!result!produces!either!no!labeling!effect!or!a!positive!labeling!effect.!

Answer!!!! !

Selected!Answer:!! !True!

Correct!Answer:!! !True!!

!! !

Question!2!!

4!out!of!4!points!

! !

!

A!comparison!of!clinically!diagnosed!versus!autopsyconfirmed!myocardial!

infarctions!was!performed!among!1000!consecutive!deceased!patients,!as!

shown!in!the!table!

!!!

Clinical!

diagnosis!

!!!!!!Autopsy!findings! !!

!

Total!!MI! No!MI!

MI! !!160! !!!!!!80! 240!

No!MI! !!40! !!!!720! 760!

Total! !!200! !!!!800! 1,000!

!! !



!!

!

From!these!data,!the!negative!predictive!value!of!the!clinical!diagnosis!was!

closest!to!

Answer!!

Selected!Answer:! !b.!!!

95%!!

Correct!Answer:! !b.!!!

95%!!!

!! !

Question!3!!

4!out!of!4!points!

! !

!

Screening!tests!are!part!of!!

Answer!! !!!

Selected!Answer:! !d.!!!

a!and!b!

Correct!Answer:! !d.!!!

a!and!b!!

!! !

Question!4!!

4!out!of!4!points!

! !

!

The!degree!of!the!burden!of!suffering!caused!by!the!condition!is!decided!

based!on!

Answer!!!! !


all!of!the!above!


all!of!the!above!!

!! !

Question!5!!

4!out!of!4!points!

! !

!

Screenig!tests!are!part!of!many!primary!and!all!secondary!prevention!activities.!

Answer!!!! !


Correct!Answer:!! !True!! !! !Question!6!!

4!out!of!4!points!

! !

!

An!abnormal!result!of!a!screening!test!in!a!person!without!disease!is!

Answer!! !!!

Selected!Answer:! !d.!!!!! !



falsepositive!


falsepositive!!

Question!7!!

4!out!of!4!points!! !

!

The!incidence!method!can!be!used!to!calculate!sensitivity!for!cancer!screening!tests!

Answer!!!! !

Selected!Answer:! !a.!!!True!

Correct!Answer:! !a.!!!

True!!

!! !

Question!8!!


!

Simple,!quick!examinations!such!as!blood!pressure!determinations!are!ideal!

screening!tests.!

Answer!!!! !

Selected!Answer:! !a.!!!

True!


True!!

!! !

Question!9!!


!

Treatments!in!primary!prevention!is!(are)!!

Answer!! !!!

Selected!Answer:! !c.!!!

immunization!


all!of!the!above!!

!! !

Question!10!!

4!out!of!4!points!

! !

!

A!screening!test!for!the!developmental!disabilities!in!children!fails!to!detect!a!substantial!proportion!of!children!with!such!disabilities.!Select!the!most!

appropriate!limitation!for!applying!results!from!this!screening!test.!!!

Answer!!

!! !

Selected!Answer:! !b.!!!Low!sensitivity! !!!




Low!sensitivity!!

Question!11!!

0!out!of!4!points!

! !

!

Which!one!of!the!following!is!a!consequence!of!overdiagnosis!in!screening?!Answer!! !!!

Selected!

Answer:!

!d.!!!

A!decrease!in!the!calculated!sensitivity!of!the!screening!

test.!

Correct!

Answer:!

!e.!!!

An!increase!in!the!observed!5year!survival!for!the!target!

disease.!!

!! !

Question!12!!

4!out!of!4!points!

! !

!

The!prior!probability!of!a!disease!is!equivalent!to!which!of!the!following?!

Answer!! !!!


prevalence!!

Correct!Answer:! !c.!!!

prevalence!!!

!! !

Question!13!!

4!out!of!4!points!

! !

!

Clinicians'!efforts!are!aimed!at!preventing!the!untimely!occurrences!of!the!five!Ds:!!Answer!!

!! !


disease,!disability,!discomfort,!dissatisfaction,!and!death!

Correct!Answer:! !a.!!!disease,!disability,!discomfort,!dissatisfaction,!and!death!

!

!! !

Question!14!!

0!out!of!4!points!

! !

!

When!randomized!controlled!trial!is!difficult!to!conduct,!case!series!in!which!a!group!of!people!participating!in!a!screening!program!are!followed!over!

time,!is!an!appropriate!method!to!use!for!the!evaluation!of!the!effectiveness!

of!the!screening!program.!!

Answer!!

!! !

Selected!Answer:! !a.!!!True! !!!




False!!

Question!15!!

0!out!of!4!points!

! !

!

The!positive!predictive!value!of!a!screening!test!for!breast!cancer!will!increase!if!the!test!is!performed!on!women!with!family!history!of!breast!

cancer.!

Answer!!

!! !

Selected!Answer:! !b.!!!False!


True!!

!! !

Question!16!!

4!out!of!4!points!

! !

!

More!aggressive!forms!of!a!disease!are!more!likely!to!be!picked!up!in!a!

screening!program.!

Answer!!!! !


False!


False!!

!! !

Question!17!!

0!out!of!4!points!

! !

!

Among!1000!women!without!breast!cancer,!screening!mammograms!are!normal!for!920!women.!!Select!the!most!appropriate!measure!from!the!

following!lettered!options!

Answer!!

!! !


sensitivity!!


specificity!!!

!! !

Question!18!!


!

A!comparison!of!clinically!diagnosed!versus!autopsyconfirmed!myocardial!

infarctions!was!performed!among!1000!consecutive!deceased!patients,!as!

shown!in!the!table!

!!

!

Clinical! !!!!!!Autopsy!findings! !!

!! !



diagnosis! !MI! No!MI! !

Total!

MI! !!160! !!!!!!80! 240!

No!MI! !!40! !!!!720! 760!

Total! !!200! !!!!800! 1,000!

!!!

From!these!data,!the!prevalence!of!myocardial!infarction!at!autopsy!was!

closest!to!Answer!!

Selected!Answer:! !e.!!!

20%!

Correct!Answer:! !e.!!!

20%!!

!! !

Question!19!!4!out!of!4!points!

! !

!

Low!predictive!values!of!a!screening!tests!are!usually!caused!by!

Answer!! !!!


both!a!and!c!


both!a!and!c!!

!! !

Question!20!!

0!out!of!4!points!

! !

!

A!diagnostic!test,!but!not!a!screening!test,!requires!a!gold!standard.!Answer!! !!!


True!


False!!

!! !

Question!21!!

0!out!of!4!points!

! !

!

When!prevalence!is!low,!the!negative!predictive!value!of!a!screening!test!is!likely!to!be!high.!

Answer!!!! !


False!


True!!

!! !



Question!22!!

0!out!of!4!points!

! !

!

The!major!purpose!of!randomization!is!to!minimize!the!differences!between!

subjects!in!the!screened!group!and!those!in!the!control!group.!

Answer!!!! !

Selected!Answer:! !!![None!Given]!!

Correct!Answer:! !!![None]!!!

!! !

Question!23!!

4!out!of!4!points!

! !

!

Among!750!patients!with!normal!screening!test!results!for!serum!

cholesterol,!50!actually!have!elevated!serum!cholesterol.!!Select!the!most!

appropriate!measure!from!the!following!lettered!options!Answer!!

!! !


falsenegative!


falsenegative!!

!! !

Question!24!!

4!out!of!4!points!

! !

!

A!type!of!prevention!that!is!particularly!important!in!the!management!of!

patients!having!a!fatal!disease.!!

Answer!!!! !


tertiary!prevention!!


tertiary!prevention!!!

!! !

Question!25!!

4!out!of!4!points!

! !

!

When!lead!time!is!very!short!treatment!of!the!medical!condition!found!on!

screening!can!be!very!effective!

Answer!!!! !


False!


False!!

!! !

Question!26!!

4!out!of!4!points!

! !

!

Most!primary!prevention!is!done!in!clinical!settings!!! !



Answer!!


False!


False!!

!! !

Question!27!!

4!out!of!4!points!

! !

!

Among!500!persons!with!positive!screening!tests!for!antibodies!to!the!human!immunodeficiency!virus!(HIV),!492!are!infected!with!the!virus.!!

Select!the!most!appropriate!measure!from!the!following!lettered!options!Answer!!

!! !


positive!predictive!value!!

Correct!Answer:! !b.!!!positive!predictive!value!!

!

!! !

Question!28!!

4!out!of!4!points!

! !

!

A!bias!occurs!because!the!proportion!of!slowgrowing!lesions!diagnosed!

during!screening!is!greater!than!the!proportion!of!those!diagnosed!during!

usual!medical!care!is!called!

Answer!!

!! !


lengthtime!bias!

Correct!Answer:! !b.!!!lengthtime!bias!

!

!! !

Question!29!!

4!out!of!4!points!

! !

!

A!screening!measure!may!be!invalid!and!reliable.!

Answer!! !!!



!! !

Question!30!!

4!out!of!4!points!

! !

!

Ascertainment!bias!in!determining!the!cause!of!death!does!not!affect!the!

estimation!of!the!screening!effect.!Answer!!

!! !

Selected!Answer:!! !False!

Correct!Answer:!! !False!!

!! !

Sunday,!March!24,!2013!11:48:33!AM!EDT!



OK!!

!Question!1!.0!out!of!4!points!

!!!!Which!of!the!following!best!define!specificity?!

Answer!!!Selected!Answer:!!b.!!!Proportion!of!people!with!a!negative!test!who!do!ot!have!the!disease.!!

Correct!Answer:!!c.!!!

Proportion!of!people!without!the!disease!who!have!a!negative!test.!!

!!

.!Question!2!.4!out!of!4!points!

!!!

!Ascertainment!bias!in!determining!the!cause!of!death!does!not!affect!the!estimation!

of!the!screening!effect.!

!

Answer!!!Selected!Answer:!!!False!!Correct!Answer:!!!False!!

!!.!Question!3!.4!out!of!4!points!

!!!

!The!positive!predictive!value!of!a!screening!test!for!breast!cancer!will!increase!if!the!test!is!performed!on!women!with!family!history!of!breast!cancer.!

Answer!!!Selected!Answer:!!a.!!!

True!!

Correct!Answer:!!a.!!!True!!

!!


!!!

!Hand!washing!to!stop!bacteria!and!viruses!from!spreading!is!classified!as!!

Answer!!!

Selected!Answer:!!a.!!!

primary!prevention!!Correct!Answer:!!a.!!!

primary!prevention!!


!!!!Getting!a!young!person!to!quit!smoking!is!an!example!of!

Answer!!!

Selected!Answer:!!b.!!!

secondary!prevention!!

Correct!Answer:!!a.!!!





!!!!Federal!laws!require!rigorous!evidence!of!efficacy!for!behavioral!counseling!

methods!before!these!methods!are!approved!for!use.!Answer!!!Selected!Answer:!!!False!!

Correct!Answer:!!!False!!

!!


!!!

!Ocular!antibiotic!prophylaxis!of!all!newborns!to!prevent!gonococcal!opthalmia!

neonatorum!is!classified!as!

Answer!!!

Selected!Answer:!!d.!!!

both!primary!and!secondary!prevention!!Correct!Answer:!!a.!!!chemoprevention!!


!!!

!The!percentage!of!falsepositive!in!screening!mammograms!is!approximately!!Answer!!!

Selected!Answer:!!a.!!!10%!!


10%!!!!


!!!

!All!the!following!clinical!activities!are!considered!tertiary!prevention!except!

Answer!!!

Selected!Answer:!!e.!!!

Treating!high!cholesterol!!

Correct!Answer:!!e.!!!Treating!high!cholesterol!!

!!

.!Question!10!.4!out!of!4!points!!!!

!The!degree!of!the!burden!of!suffering!caused!by!the!condition!is!decided!based!on!Answer!!!


all!of!the!above!!

Correct!Answer:!!d.!!!

all!of!the!above!!



!!


!Flouridation!of!water!would!be!an!example!of!!Answer!!!

Selected!Answer:!!a.!!!primary!prevention!!Correct!Answer:!!a.!!!


!!


!!!

!All!activities!in!medicine!could!be!defined!as!prevention!

Answer!!!


True!!

Correct!Answer:!!a.!!!True!!!!


!Which!one!of!the!following!statements!related!to!length!bias!is!TRUE?!

!Answer!!!

Selected!Answer:!!c.!!!Slowly!progressing!cases!of!disease!are!more!likely!to!be!detected!during!screening!

than!rapidly!progressing!cases.!

!!Correct!Answer:!!c.!!!

Slowly!progressing!cases!of!disease!are!more!likely!to!be!detected!during!screening!

than!rapidly!progressing!cases.!

!!

!!


!!!

!When!prevalence!is!low,!the!negative!predictive!value!of!a!screening!test!is!likely!to!be!high.!

Answer!!!

Selected!Answer:!!a.!!!True!!

Correct!Answer:!!a.!!!True!!

!!


!!!



!Among!100!patients!with!Alzheimer’s!disease,!15!subjects!score!within!the!normal!

range!on!a!battery!of!tests!of!cognitive!performance.!Select!the!most!appropriate!measure!from!the!following!lettered!options!

!Answer!!!

Selected!Answer:!!f.!!!sensitivity!!!Correct!Answer:!!f.!!!

sensitivity!!!

!!


!!!

!Subjects!who!do!not!comply!with!their!randomized!assignment!should!not!be!

included!in!the!analysis!of!the!screening!effect.!

!

Answer!!!

Selected!Answer:!!!False!!Correct!Answer:!!!False!!!!


!Typically,!many!health!care!professionals!practice!what!type!of!disease!prevention?!

Answer!!!Selected!Answer:!!c.!!!

Tertiary!!Correct!Answer:!!c.!!!

Tertiary!!


!!!

!Chest!radiographs!tend!to!lead!to!earlier!recognition!of!lung!cancers,!with!no!

impact!on!delaying!the!eventual!time!of!death.!Select!the!most!appropriate!

limitation!for!applying!results!from!this!screening!test.!!!

!

Answer!!!

Selected!Answer:!!c.!!!Leadtime!bias!

!!

Correct!Answer:!!c.!!!Leadtime!bias!

!!!!


!!!

!Which!one!of!the!following!is!a!consequence!of!overdiagnosis!in!screening?!

!



Answer!!!

Selected!Answer:!!d.!!!An!increase!in!the!observed!5year!survival!for!the!target!disease.!

!!Correct!Answer:!!d.!!!

An!increase!in!the!observed!5year!survival!for!the!target!disease.!!!!!


!!!

!Which!of!the!following!should!not!be!considered!when!deciding!the!appropriate!use!

of!a!screening!test?!!

Answer!!!


Whether!the!disease!condition!is!sufficiently!imprtant!for!the!individual!and!the!

commuity.!!

Correct!Answer:!!e.!!!All!of!the!above.!!!!


!Taking!preventative!steps!that!stop!a!health!problem!before!it!starts!is!called!


primary!prevention!!Correct!Answer:!!a.!!!



!!!

!All!the!following!terms!are!used!for!determining!how!good!is!the!screening!test!

except:!

Answer!!!


profitability!!

Correct!Answer:!!b.!!!profitability!!

!!


!When!lead!time!is!very!short!treatment!of!the!medical!condition!found!on!screening!can!be!very!effective!

Answer!!!


False!!

Correct!Answer:!!b.!!!



False!!


!!!!Among!1000!women!without!breast!cancer,!screening!mammograms!are!normal!

for!920!women.!!Select!the!most!appropriate!measure!from!the!following!lettered!options!!

Answer!!!


specificity!!!

Correct!Answer:!!e.!!!

specificity!!!

!!


!!!

!More!aggressive!forms!of!a!disease!are!more!likely!to!be!picked!up!in!a!screening!program.!Answer!!!

Selected!Answer:!!b.!!!False!!


False!!!!


!The!first!time!that!screening!is!carried!out!is!called!an!incidence!screen.!

Answer!!!Selected!Answer:!!b.!!!

False!!


False!!

!!


!!!

!When!applied!in!the!general!population,!a!screening!test!that!is!normal!among!99%!of!unaffected!persons!and!abnormal!among!97%!of!affected!persons!nevertheless!

yields!a!low!positive!predictive!value.!Select!the!most!appropriate!limitation!for!

applying!results!from!this!screening!test.!!!!

Answer!!!Selected!Answer:!!d.!!!

Low!specificity!

!!


Low!prevalence!



!!


!!!!Effective!counseling!methods!could!promote!health!more!than!most!anything!else!a!

clinician!can!do.!Answer!!!Selected!Answer:!!a.!!!

True!!


True!!

!!


!!!

!Which!is!the!best!way!to!avoid!biases!when!evaluating!the!efficacy!of!a!screening!

test!or!treatment!in!a!clinical!trial?!

Answer!!!Selected!Answer:!!c.!!!Randomization!!

Correct!Answer:!!c.!!!Randomization!!

!!


!Pap!smears!and!mammograms!are!examples!of!!Answer!!!


secondary!prevention!!Correct!Answer:!!b.!!!


!!

.Sunday,!March!24,!2013!6:29:53!PM!EDT!

!

OK!!

.!

Question!1!.4!out!of!4!points!

!!!

!A!comparison!of!clinically!diagnosed!versus!autopsyconfirmed!myocardial!

infarctions!was!performed!among!1000!consecutive!deceased!patients,!as!shown!in!

the!table!

!

!!!

!

!



!

Clinical!!

diagnosis!!!!!!!!Autopsy!findings!

!!!!!

!

!

!

Total!

!!

!MI!

!No!MI!

!!

MI!!!!160!!!!!!!!80!

!240!!!

No!MI!

!!!40!!!!!!720!

!760!!!

Total!

!!!200!!!!!!800!

!1,000!

!!

!

!

!!

!

!!

!

From!these!data,!the!prevalence!of!myocardial!infarction!at!autopsy!was!closest!to!!

Answer!!!Selected!Answer:!!e.!!!

20%!!


20%!!

!!




!!!!When!lead!time!is!very!short!treatment!of!the!medical!condition!found!on!screening!

can!be!very!effective!Answer!!!

Selected!Answer:!!b.!!!False!!Correct!Answer:!!b.!!!

False!!

!!


!!!

!For!a!screening!to!be!successful!you!need!a!suitable!!

Answer!!!


all!of!the!above!!

Correct!Answer:!!d.!!!all!of!the!above!!!!


!Which!of!the!following!measures!is!conditioned!on!having!a!positive!test?!!


positive!predictive!value!!!Correct!Answer:!!c.!!!

positive!predictive!value!!!


!!!

!Screenig!tests!are!part!of!many!primary!and!all!secondary!prevention!activities.!

Answer!!!

Selected!Answer:!!!True!!

Correct!Answer:!!!True!!

!!


!A!sreening!measure!may!be!unreliable!but!valid.!

Answer!!!Selected!Answer:!!!False!!

Correct!Answer:!!!False!!!!


!!!



!For!many!diseases,!there!is!a!critical!point!in!time!beyond!which!therapy!is!less!

effective.!For!most!cancers,!the!critical!point!occurs!when!the!primary!tumor!metastasizes.!When!must!the!critical!point!occur!for!screening!to!be!effective?!

!Answer!!!

Selected!Answer:!!c.!!!After!the!disease!is!detectable!but!before!it!produces!symptoms.!!!


After!the!disease!is!detectable!but!before!it!produces!symptoms.!

!!

!!


!!!

!Treatments!in!primary!prevention!is!(are)!!

Answer!!!

Selected!Answer:!!d.!!!all!of!the!above!!Correct!Answer:!!d.!!!

all!of!the!above!!!!


!!!!Selective!screening!involves!applying!the!screening!test!to!which!of!the!following?!


Highrisk!groups!!

Correct!Answer:!!b.!!!Highrisk!groups!!

!!


!!!

!A!screening!measure!may!be!invalid!and!reliable.!

Answer!!!


Correct!Answer:!!!True!!!!


!!!!All!the!following!diseases!are!suitable!for!screening!except:!


lung!cancer!!


lung!cancer!!

!!




!!!!The!first!time!that!screening!is!carried!out!is!called!an!incidence!screen.!


False!!Correct!Answer:!!b.!!!False!!

!!


!!!

!Slowprogressing!cases!of!disease!with!a!better!prognosis!are!more!likely!to!be!

identified!than!fasterprogressing!cases!of!a!disease!with!a!poorer!prognosis.Thus,!

cases!diagnosed!through!screening!tend!to!have!better!prognosis!than!the!average!

of!all!cases.!!

Answer!!!

Selected!Answer:!!c.!!!lengthtime!bias!!!Correct!Answer:!!c.!!!

lengthtime!bias!!!!!


!!!!Pap!smears!and!mammograms!are!examples!of!!



Correct!Answer:!!b.!!!secondary!prevention!!

!!


!!!

!Among!100!patients!with!Alzheimer’s!disease,!15!subjects!score!within!the!normal!

range!on!a!battery!of!tests!of!cognitive!performance.!Select!the!most!appropriate!

measure!from!the!following!lettered!options!

!Answer!!!


sensitivity!!!Correct!Answer:!!b.!!!

sensitivity!!!!!


!!!

!Ocular!antibiotic!prophylaxis!of!all!newborns!to!prevent!gonococcal!opthalmia!

neonatorum!is!classified!as!



Answer!!!

Selected!Answer:!!a.!!!chemoprevention!!

Correct!Answer:!!a.!!!chemoprevention!!

!!.!Question!17!.4!out!of!4!points!!!!

!Hand!washing!to!stop!bacteria!and!viruses!from!spreading!is!classified!as!!

Answer!!!





!!


!!!!A!comparison!of!clinically!diagnosed!versus!autopsyconfirmed!myocardial!infarctions!was!performed!among!1000!consecutive!deceased!patients,!as!shown!in!

the!table!!

!

!!!

!!

Clinical!

!diagnosis!

!!!!!!!Autopsy!findings!

!!

Total!

!!

!MI!

!No!MI!

!!MI!

!!!160!

!!!!!!!80!!240!

!!No!MI!

!!!40!

!!!!!720!

!760!

!!



Total!

!!!200!!!!!!800!

!1,000!!!

!!From!these!data,!the!sensitivity!of!the!clinical!diagnosis!was!closest!to!

!

Answer!!!


80%!!


80%!!

!!


!!!!Sensitivity,!specificity,!predictive!value,!and!cost!are!independent!of!each!other.!Answer!!!

Selected!Answer:!!!False!!Correct!Answer:!!!False!!

!!


!Which!of!the!following!best!defines!the!"yield"!of!a!screening!test?!!Answer!!!

Selected!Answer:!!c.!!!

How!much!of!a!disease!the!screening!test!can!detect!in!the!screening!process.!!!Correct!Answer:!!c.!!!

How!much!of!a!disease!the!screening!test!can!detect!in!the!screening!process.!!!

!!


!!!

!The!prior!probability!of!a!disease!is!equivalent!to!which!of!the!following?!

!


prevalence!!!

Correct!Answer:!!c.!!!prevalence!!!


!!!

!Subjects!who!do!not!comply!with!their!randomized!assignment!should!not!be!

included!in!the!analysis!of!the!screening!effect.!

!



Answer!!!



!!!!All!the!following!terms!are!used!for!determining!how!good!is!the!screening!test!except:!

Answer!!!


profitability!!


profitability!!

!!


!!!

!Laws!mandating!seatbelt!use!in!automobile!and!helmet!use!on!motorcycles!are!considered!Answer!!!

Selected!Answer:!!a.!!!primary!prevention!!


primary!prevention!!!!


!A!screening!test!for!the!developmental!disabilities!in!children!fails!to!detect!a!

substantial!proportion!of!children!with!such!disabilities.!Select!the!most!appropriate!limitation!for!applying!results!from!this!screening!test.!!!

!

Answer!!!


Low!sensitivity!

!!


Low!sensitivity!!!

!!


!Getting!a!young!person!to!quit!smoking!is!an!example!of!Answer!!!







!!


!The!screening!test!looks!better!than!it!actually!is,!because!younger,!healthier!people!are!more!likely!to!get!the!test.!!

Answer!!!Selected!Answers:!!!b.!!!selection!bias!!

!

!!!

Correct!Answers:!!!b.!!!

selection!bias!!

!

!!!

!!


!!!!Which!of!the!following!should!not!be!considered!when!deciding!the!appropriate!use!of!a!screening!test?!!


All!of!the!above.!!

Correct!Answer:!!e.!!!All!of!the!above.!!


!!!

!Which!of!the!following!best!define!specificity?!Answer!!!





!!


!!!!The!best!way!to!establish!the!efficacy!of!treatment!is!with!a!!

Answer!!!

Selected!Answer:!!b.!!!randomized!controlled!trial!!

Correct!Answer:!!b.!!!randomized!controlled!trial!!

!!

.Sunday,!March!24,!2013!6:44:08!PM!EDT!

!• Question 1



0 out of 4 points

The major purpose of randomization is to minimize the differences betweensubjects in thescreened group and those in the control group. Answer

Selected Answer:[None Given]

Correct Answer:[None]


To be suitable for screening, disease treatment must be effective at an earlier stage.Answer

Selected Answer:a.

True

Correct Answer:a.

True


Typically, many health care professionals practice what type of disease prevention?Answer

Selected Answer:c.

Tertiary

Correct Answer:c.

Tertiary


Only conditions posing threats to life or health should be included in

preventive care.Answer

Selected Answer: b.

False

Correct Answer:a.

True


Which of the following should not be considered when deciding the

appropriate use of a screening test?Answer



Selected Answer:e.

All of the above.

Correct Answer:e.

All of the above.


A type of prevention that is particularly important in the management of

patients having a fatal disease.Answer

Selected Answer:c.

tertiary prevention

Correct Answer:c.

tertiary prevention


Getting a young person to quit smoking is an example of Answer

Selected Answer:a.

primary prevention

Correct Answer:a.

primary prevention


For many diseases, there is a critical point in time beyond which therapy is less

effective. For most cancers, the critical point occurs when the primary tumor metastasizes. When must the critical point occur for screening to be effective?

Answer

Selected

Answer: b.

After the disease is detectable and after it producessymptoms.

Correct Answer:

c.After the disease is detectable but before it produces

symptoms.


Most primary prevention is done in clinical settingsAnswer



Selected Answer: b.

False

Correct Answer: b.

False




Clinical

diagnosis

Autopsy findings

Total

MI No MI

MI 160 80 240

No MI 40 720 760

Total 200 800 1,000

From these data, the specificity of the clinical diagnosis was closest to

Answer

Selected Answer: d.

90%

Correct Answer:d.

90%


A diagnostic test, but not a screening test, requires a gold standard.Answer

Selected Answer: b.

False

Correct Answer: b.

False


Effective counseling methods could promote health more than most anything



else a clinician can do.Answer

Selected Answer:a.

True

Correct Answer: a.

True


Simple, quick examinations such as blood pressure determinations are ideal

screening tests.Answer

Selected Answer:a.

True

Correct Answer: a.

True


Compliant patients tend to have better prognoses regardless of screening.Answer

Selected Answer:a.

True

Correct Answer:

a.True


The degree of the burden of suffering caused by the condition is decided based

onAnswer

Selected Answer:d.

all of the above

Correct Answer:

d.all of the above


The first time that screening is carried out is called an incidence screen.Answer



Selected Answer: b.

False

Correct Answer: b.

False


The positive predictive value for test results will decrease after the first round

of screening.Answer

Selected Answer:a.

True

Correct Answer:a.

True


To be suitable for screening, a particular test needs to beAnswer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above



Selected Answer: b.

secondary

Correct Answer: b.

secondary

• Question 20

4 out of 4 points

Among 750 patients with normal screening test results for serum cholesterol,

50 actually have elevated serum cholesterol. Select the most appropriatemeasure from the following lettered options

Answer

Selected Answer:c.

false-negative



Correct Answer:c.

false-negative


Screening tests are totally different from diagnostic tests.Answer

Selected Answer: b.

False

Correct Answer: b.

False


Which of the following is not a primary requirement for conducting screening

for disease controlAnswer

Selected Answer:c.


Correct Answer:c.



Screening tests are part of Answer

Selected Answer:d.

a and b

Correct Answer:d.

a and b


Regular ophthalmologic examination for early diabetic retinopathy is a form of Answer

Selected Answer: b.


Correct Answer:c.

tertiary prevention




It is unethical to accept a certain risk for diagnostic test applied to sick patientsseeking help for specific complaints.Answer


Correct Answer: False


A prevention program that is oriented to the most experienced drug user would

be referred to as

Answer

Selected Answer:c.

tertiary

Correct Answer:c.

tertiary


Which one of the following is a consequence of overdiagnosis in screening?

Answer

Selected

Answer: b.

An increase in the observed 5-year survival for the targetdisease.

Correct Answer: b.

An increase in the observed 5-year survival for the targetdisease.


Which is the best way to avoid biases when evaluating the efficacy of a

screening test or treatment in a clinical trial?Answer

Selected Answer:c.

Randomization

Correct Answer: c.

Randomization


The screening test looks better than it actually is, because younger, healthier

people are more likely to get the test.Answer



Selected Answers: b.

selection bias

Correct Answers: b.

selection bias


A screening test for the developmental disabilities in children fails to detect a

substantial proportion of children with such disabilities. Select the mostappropriate limitation for applying results from this screening test.Answer

Selected Answer: b.

Low sensitivity

Correct Answer: b.

Low sensitivity


The positive predictive value for test results will decrease after the first round

of screening.Answer

Selected Answer:a.

True

Correct Answer:a.

True


Compliant patients tend to have better prognoses regardless of screening.Answer

Selected Answer:a.

True

Correct Answer:a.

True


A comparison of clinically diagnosed versus autopsy-confirmed gastric and

peptic ulcers was performed in 10,000 consecutive deceased patients, as shown



in the table

Clinical

diagnosis

Autopsy findings

Total

Ulcer No ulcer

Ulcer 130 20 150

No ulcer 170 9,680 9,850

Total 300 9,700 10,000

From these data, the sensitivity of the clinical diagnosis was closest to

Answer

Selected Answer:a.

87%

Correct Answer:e.

43%


The lead time for lung cancer is very long.Answer

Selected Answer: b.

False

Correct Answer: b.

False


The prior probability of a disease is equivalent to which of the following?

Answer

Selected Answer:

a. prevalence

Correct Answer:a.

prevalence


As the true positive of a screening test increases, which of the following



occurs?Answer

Selected Answer:c.


Correct Answer: c.



Percent 5-year survival from diagnosis is a statistic that is often used in studies

involvingdiseases with a significant mortality rate. In the context of ahypothetic study of a new screening program, investigators compared 5-year

survival between the screening-detected cases in the program and cases presenting with symptoms outside the program. Which one of the following

statements about these comparisons of 5-year survival is TRUE?

Answer

Selected Answer:e.

They are affected by recall bias.

Correct Answer: b.

They are affected by overdiagnosis bias.


Which of the following should not be considered when deciding the

appropriate use of a screening test?

Answer

Selected Answer:e.

All of the above.

Correct Answer:e.

All of the above.


All activities in medicine could be defined as preventionAnswer

Selected Answer:a.

True

Correct Answer:a.

True




More aggressive forms of a disease are more likely to be picked up in a

screening program.Answer

Selected Answer: b.

False

Correct Answer: b.

False


Screening for very rare disease is beneficial to very few peopleAnswer

Selected Answer:a.

True

Correct Answer: a.

True


All the following terms are used for determining how good is the screening test

except:Answer

Selected Answer: b.

profitability

Correct Answer: b.

profitability


Sensitivity, specificity, predictive value, and cost are independent of eachother.Answer




A comparison of clinically diagnosed versus autopsy-confirmed myocardialinfarctions was performed among 1000 consecutive deceased patients, as

shown in the table



Clinical diagnosis

Autopsy findings Total

MI No MI

MI 160 80 240

No MI 40 720 760

Total 200 800 1,000

From these data, the false negative rate of the clinical diagnosis was closest to

Answer

Selected Answer:a.

8%

Correct Answer:d.

4%


The identification of asymptomatic disease or risk factors is calledAnswer

Selected Answer: b.

screening

Correct Answer: b.

screening


The period of time between the detection of a medical condition by screening

and when it ordinarily would be diagnosed because a patient experiencessymptoms and seeks medical care is calledAnswer

Selected Answer:c.

lead time

Correct Answer:c.

lead time


Clinicians' efforts are aimed at preventing the untimely occurrences of the fiveDs:Answer

Selected Answer:c.

disease, disability, discomfort, dissatisfaction, and death

Correct Answer:c.



disease, disability, discomfort, dissatisfaction, and death


Selective screening involves applying the screening test to which of the

following?Answer

Selected Answer:a.

High-risk groups

Correct Answer:a.

High-risk groups


The major purpose of randomization is to minimize the differences between

subjects in thescreened group and those in the control group. Answer


Correct Answer:[None]


Which of the following is not a primary requirement for conducting screeningfor disease controlAnswer

Selected Answer:c.


Correct Answer:c.



The screening test looks better than it actually is, because younger, healthier

people are more likely to get the test.Answer

Selected Answers:d.

selection bias

Correct Answers:d.

selection bias





Selected Answer: b.

secondary

Correct Answer: b.

secondary


Regular ophthalmologic examination for early diabetic retinopathy is a form of Answer

Selected Answer: c.

tertiary prevention

Correct Answer:c.

tertiary prevention


Flouridation of water would be an example of Answer

Selected Answer:a.

primary prevention

Correct Answer:a.

primary prevention


Handing out pamphlets on how to reduce bad cholesterol level in subjects withhypercholesterolemia is an example of Answer

Selected Answer:a.

primary prevention

Correct Answer: b.



All the following activities are considered secondary prevention except:



Answer

Selected Answer: b.


Correct Answer: b.



Typically, many health care professionals practice what type of disease prevention?Answer

Selected Answer:c.

Tertiary

Correct Answer:c.

Tertiary


Lack of compliance in the screened group results in an overestimation of thescreening effect. Answer



• Question 29

0 out of 4 points



Clinical diagnosis

Autopsy findings Total

MI No MI

MI 160 80 240

No MI 40 720 760

Total 200 800 1,000

From these data, the sensitivity of the clinical diagnosis was closest to

Answer

Selected Answer:c.

67%

Correct Answer: b.



80%


Which is the best way to avoid biases when evaluating the efficacy of a

screening test or treatment in a clinical trial?Answer

Selected Answer: b.

Randomization

Correct Answer: b.

Randomization

!




In decision tree models for prognosis, every tree contains terminal nodes thatrepresent “subsequent prognosis” for a particular combination of patient

characteristics and events.

Answer Selected Answer:

True

Correct Answer:True


Overestimating probability of a diagnosis when the correct diagnosis is already

known

Answer

Selected Answer: b.

Hindsight error

Correct Answer: b.

Hindsight error


The quantitative expression of the value or importance of a given variable is

called

Answer

Selected Answer:c.

Assigned weight

Correct Answer:d.

Utility


Markov chain is a special type of Markov process in which the transition

probabilities are constant over time.Answer


Correct Answer: True


Decision analysis is appropriate for events that reoccur throughout a lifetime.Answer






Decision analyses

Answer

Selected Answer:c.

a and b

Correct Answer:c.

a and b


The maximin criteria is a(n) __________ criteria. Answer

Selected Answer: c.

Pessimistic

Correct Answer:c.

Pessimistic


The standards that define the best thinking for achieving the thinker’s goals. Answer

Selected Answer:c.

Prescriptive models

Correct Answer:d.

Normative models


Decision making situations can be categorized along a scale which rangesfrom: Answer

Selected Answer:

b.Certainty to risk to uncertainty to ambiguity

Correct Answer: b.

Certainty to risk to uncertainty to ambiguity


The Markov process is analogous to a utility in an ordinary decision tree.



Answer


Correct Answer:True

• Question 11

4 out of 4 points

Used to find the alternative that maximizes the maximum payoff Answer

Selected Answer:e.

Maximax

Correct Answer:e.

Maximax


Choosing riskier treatments when they are described in negative (e.g.,mortality) rather than positive (e.g., survival) terms. Answer

Selected Answer: b.

Framing bias

Correct Answer: b.

Framing bias


Decision analyses always require comparison of at least two clinical strategies.

One strategy ought to contain advantages and countervailing disadvantages.Answer


Correct Answer:True


A state of a Markov model may be defined as

Answer

Selected Answer: d.

a or b

Correct Answer:d.

a or b




The states of a Markov model describe a partial set of interrelated conditions

under which a system operates.Answer


Correct Answer:

False


A weighted average compromise between optimistic and pessimistic

Answer

Selected Answer:a.

Hurwicz criterion

Correct Answer:a.

Hurwicz criterion


EMV refers to

Answer

Selected Answer:c.

expected monetary value

Correct Answer:c.

expected monetary value

• Question 18

4 out of 4 points

In influence diagram, decision nodes are depicted as

Answer

Selected Answer:a.

squares or rectangles

Correct Answer:a.

squares or rectangles


Any problem that can be represented in a decision table can also be graphically

illustrated in a: Answer

Selected Answer:c.

decision tree.



Correct Answer:c.

decision tree.


The difference between the optimal profit and actual payoff for a decision Answer

Selected Answer:d.

Minimax regret

Correct Answer:d.

Minimax regret


Models describe how people ought to think. Answer

Selected Answer:d.

Prescriptive models

Correct Answer:d.

Prescriptive models


A quantitative method used to assess the relative value of different options to

deal with a clinical choice under conditions of uncertainty. Answer

Selected Answer:c.

Decision analysis

Correct Answer:c.

Decision analysis


The utility that is associated with spending one cycle in a particular state is

referred to as

Answer

Selected Answer: b.

incremental utility

Correct Answer: b.

incremental utility




The Decision-making process involve

Answer

Selected Answer:d.

All of the above

Correct Answer:d.

All of the above


The Laplace decision criterion is also known as Answer

Selected Answer: b.

equally likely

Correct Answer: b.

equally likely


A point in a decision tree at which several choices are possible. Answer

Selected Answer:a.

Decision node

Correct Answer:a.

Decision node


Providing more detail of an event increases its judged probability. Answer

Selected Answer:d.

Description bias

Correct Answer:d.

Description bias


“The process of systematically finding, appraising, and using

contemporaneous research findings as the basis for clinical decisions” is called

Answer



Selected Answer:d.

Systematic review

Correct Answer:d.

Systematic review


Maximax is also called decisions under uncertainty.Answer


Correct Answer:True


Which of the following is (are) types of decision-making environments?

Answer

Selected Answer:e.

All of the above

Correct Answer:e.

All of the above


The equally likely decision criterion is also known as

Answer

Selected Answer: b.

Laplace.

Correct Answer: b.

Laplace.


Both the timing of events and the representation of events that may occur morethan once can be addressed by using a recursive decision tree.Answer


Correct Answer:True




For a decision to exist, there must be at least ---- options in response to a

problem. Answer

Selected Answer:a.

5

Correct Answer:d.

2



Selected Answer: b.

Bayes’ theorem

Correct Answer:a.

Prescriptive models


Considers all the payoffs for each alternative

Answer

Selected Answer:a.

Minimax regret

Correct Answer:

e.Laplace


A quantitative method used to assess the relative value of different options to

deal with a clinical choice under conditions of uncertainty. Answer

Selected Answer:c.

Cost-benefit analysis

Correct Answer:a.

Decision analysis


Decision making situations can be categorized along a scale which ranges

from: Answer



Selected Answer:c.

Uncertainty to certainty to risk

Correct Answer:d.

Certainty to risk to uncertainty to ambiguity


The states of a Markov model describe a partial set of interrelated conditions

under which a system operates.Answer




In Markov models (well – stroke – disabled – death ), stroke is

Answer

Selected Answer:a.

temporary states

Correct Answer:a.

temporary states


In influence diagram, squares or rectangles depict

Answer

Selected Answer: b.

decision nodes

Correct Answer: b.

decision nodes


Conventional decision analysis models assumptions include all the followingexcept:

Answer

Selected Answer:a.

Events that do not recur

Correct Answer:d.

Timing of events is important

• Question 12



4 out of 4 points

Decision-analytic models must be sufficiently complex to incorporate theimportant events and values, yet sufficiently simple to be understandable. Answer


Correct Answer:True


In order for a Markov process to terminate, it must have at least one state thatthe patient cannot leave. Such states are called

Answer

Selected Answer: b.

tunnel states

Correct Answer:

e.absorbing states


For a Markov model of three states, there will be --- transition probabilities. Answer

Selected Answer:c.

6

Correct Answer: b.

9• Question 15

4 out of 4 points

A point in a decision tree at which several choices are possible. Answer

Selected Answer:c.

Decision node

Correct Answer:c.

Decision node


Markov chain is a special type of Markov process in which the transition probabilities are constant over time.Answer




Correct Answer:True


Any problem that can be represented in a decision table can also be graphically

illustrated in a: Answer

Selected Answer:a.

utility curve.

Correct Answer:c.

decision tree.


In the medical and pharmacoeconomics literature, the states of a Markov

model often represent Answer

Selected Answer:d.

assigned probabilities

Correct Answer:a.

various levels of disease progression


The process of choosing from a number of hypothetical clinical paradigms by

comparing them in terms of model-based probabilistic outcomes is oftenreferred to asAnswer

Selected Answer:d.

hypothesis testing

Correct Answer: b.

decision analysis


Decision analysis is appropriate for events that reoccur throughout a lifetime.Answer







comparing them in terms of model-based probabilistic outcomes is oftenreferred to as

Answer

Selected Answer: b.

hypothesis testing

Correct Answer:d.

decision analysis


Used to find the alternative that maximizes the maximum payoff Answer

Selected Answer: b.

Criterion of realism

Correct Answer:a.

Maximax


Markov models are not suited for censored and intermittent data. Answer




Markov models are useful when

Answer

Selected Answer: b.

the timing of events is important.

Correct Answer:d.

all of the above


A state of a Markov model may be defined as

Answer

Selected Answer:d.

a or b



Correct Answer:d.

a or b


“The process of systematically finding, appraising, and usingcontemporaneous research findings as the basis for clinical decisions” is called

Answer

Selected Answer:c.

Systematic review

Correct Answer:c.

Systematic review


The difference between the optimal profit and actual payoff for a decision

Answer

Selected Answer:a.

Maximax

Correct Answer:c.

Minimax regret


Providing more detail of an event increases its judged probability. Answer

Selected Answer:d.

Description bias

Correct Answer:d.

Description bias


The fact that the data are censored does not imply that only intermediateendpoints are observed or that complete information regarding disease states is

unavailable for all patients. Answer


Correct Answer:True




Decision analyses always require comparison of at least two clinical strategies.

One strategy ought to contain advantages and countervailing disadvantages.Answer


Correct Answer:

True


In influence diagram, squares or rectangles depict Answer

Selected Answer:c.

chance nodes

Correct Answer:d.

decision nodes

•

Question 2 0 out of 4 points

In order for a Markov process to terminate, it must have at least one state that

the patient cannot leave. Such states are called

Answer

Selected Answer: b.

temporary states

Correct Answer:c.

absorbing states

• Question 3

0 out of 4 points

Patients who have carotid artery stenosis of more than 70% after suffering

transient ischemic attacks clearly benefit from carotid endarterectomy, asdemonstrated by the NASCET Trial. Do we need not perform a decision

analysis of this question? Answer

Selected Answer:1.

Yes

Correct Answer:2.

No


Markov models are not suited for censored and intermittent data. Answer






A point in a decision tree at which chance determines which outcome will

occur. Answer

Selected Answer:d.

Change point

Correct Answer:c.

Chance node


All the following are advantages of decision trees except:

Answer

Selected Answer:c.

Places a numerical value on likely or potential outcomes

Correct Answer:e.

High accuracy irrespective of the nature of the data


The number of patients that need to be treated with the technique beinginvestigated to prevent an unwanted outcome.

Answer

Selected Answer: b.

EMV

Correct Answer:d.

Number needed to treat


Decision analyses

Answer

Selected Answer:d.

None of the above

Correct Answer:c.

a and b




Markov process terminates irrespective of the nature of the states.Answer




Conventional decision analysis models assumptions include all the followingexcept: Answer

Selected Answer: b.

Limited time horizon

Correct Answer:a.

Timing of events is important


Markov chain is a special type of Markov process in which the transition probabilities are constant over time.Answer


Correct Answer:True


A commonly used representation of Markov processes

Answer

Selected Answer:c.

All of the above

Correct Answer: b.

State transition diagram


Estimating the probability of a disease by judging how similar the case is to a

diagnostic category or prototype; can lead to base rate neglect. Answer

Selected Answer:c.

Description bias

Correct Answer:a.

Representativeness bias




A decision problem is characterized by Answer

Selected Answer:e.

none of the above

Correct Answer:d.

all of the above


The fact that the data are censored does not imply that only intermediate

endpoints are observed or that complete information regarding disease states is

unavailable for all patients. Answer

Selected Answer: True

Correct Answer:True


The Laplace decision criterion is also known as Answer

Selected Answer:c.

minimax.

Correct Answer: b.

equally likely


The equally likely decision criterion is also known as

Answer

Selected Answer:d.

Hurwicz.

Correct Answer: b.

Laplace. • Question 18

0 out of 4 points

Markov models generally rely on the assumption that a patient’s progression

rate to the next state is dependent on his or her progression rate through

previous states.Answer







Selected Answer:c.

Descriptive models

Correct Answer:a.

Prescriptive models


Used to minimize the maximum possible loss. Answer

Selected Answer: b.

Equally likely

Correct Answer:a.

Maximin



comparing them in terms of model-based probabilistic outcomes is oftenreferred to as

Answer

Selected Answer: b.

statistical analysis

Correct Answer:d.

decision analysis


Maximax is also called decisions under uncertainty.Answer


Correct Answer:True


Markov models are useful when



Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above


Considers all the payoffs for each alternative

Answer

Selected Answer:d.

Criterion of realism

Correct Answer:e.

Laplace


All of the following are steps in the decision-making process EXCEPT: Answer

Selected Answer:d.

List alternatives

Correct Answer:e.

Compute the posterior probabilities


All the following decision making methods are deterministic except: Answer

Selected Answer:c.

Conservative

Correct Answer:d.

Markov

• Question 27

0 out of 4 points

The essence of decision making is: Answer

Selected Answer:d.

problem solving.



Correct Answer: b.

choosing between alternatives.


In the medical and pharmacoeconomics literature, the states of a Markovmodel often represent Answer

Selected Answer:d.

decision nodes

Correct Answer:c.

various levels of disease progression


For a decision to exist, there must be at least ---- options in response to a problem. Answer

Selected Answer:c.

1

Correct Answer:d.

2


The criteria of Expected Monetary Value is used for making decisions under Answer

Selected Answer:c.

risk.

Correct Answer:d.

all of the above

!


! !

!

All!the!following!are!advantages!of!decision!trees!except:!

Answer!! !!!


High!accuracy!irrespective!of!the!nature!of!the!data!!!


High!accuracy!irrespective!of!the!nature!of!the!data!!!!

!! !



Question!2!!

4!out!of!4!points!

! !

!

A!probability!model!that!predicts!the!conditional!probability!of!one!event!

given!the!occurrence!of!another!event!

Answer!!!! !


Bayes’!theorem!


Bayes’!theorem!!

!! !

Question!3!!

4!out!of!4!points!

! !

!

In!a!state!transition!diagram!each!state!is!represented!by!a!!Answer!! !!!

Selected!Answer:! !d.!!!circle!!


circle!!!

!! !

Question!4!!

4!out!of!4!points!

! !

!

Markov!models!are!useful!when!!

Answer!! !!!


all!of!the!above!

Correct!Answer:! !d.!!!all!of!the!above!

!

!! !


! !

!

Decision!analysis!is!appropriate!for!events!that!reoccur!throughout!a!

lifetime.!

Answer!!!! !



!! !

Question!6!!

4!out!of!4!points!

! !

!

The!difference!between!the!optimal!profit!and!actual!payoff!for!a!decision!

Answer!! !!!


Minimax!regret! !!!



Correct!Answer:! !b.!!!Minimax!regret!

!


! !

!

States!required!whenever!there!is!an!event!that!has!only!shortOterm!effects.!Such!states!are!defined!by!having!transitions!only!to!other!states!and!not!to!

themselves.!This!guarantees!that!the!patient!can!spend,!at!most,!one!cycle!in!

that!state.!!

Answer!!

!! !


temporary!states!


temporary!states!!

!! !

Question!8!!

4!out!of!4!points!

! !

!

For!a!Markov!model!of!three!states,!there!will!be!OOO!transition!probabilities.!!Answer!! !!!


9!

Correct!Answer:! !d.!!!9!

!

!! !


! !

!

To!examine!how!a!particular!decision!might!change!with!different!input!

data,!you!need!to!use!Answer!!

!! !


Sensitivity!analysis!

Correct!Answer:! !b.!!!Sensitivity!analysis!

!

!! !


! !

!

The!process!of!choosing!from!a!number!of!hypothetical!clinical!paradigms!by!

comparing!them!in!terms!of!modelObased!probabilistic!outcomes!is!often!

referred!to!as!!

Answer!!

!! !

Selected!Answer:! !c.!!!decision!analysis!! !!!



Correct!Answer:! !c.!!!decision!analysis!!

!


! !

!

Markov!models!are!particularly!useful!when!a!decision!problem!involves!a!risk!that!is!!

Answer!!!! !


ongoing!over!time!!


ongoing!over!time!!!

!! !

Question!12!!

4!out!of!4!points!

! !

!

A!weighted!average!compromise!between!optimistic!and!pessimistic!Answer!! !!!


Hurwicz!criterion!


Hurwicz!criterion!!

!! !

Question!13!!

4!out!of!4!points!

! !

!

verestimating!probability!of!a!diagnosis!when!the!correct!diagnosis!is!

already!known!Answer!! !! !


Hindsight!error!


Hindsight!error!!

!! !

Question!14!!

4!out!of!4!points!

! !

!

“The!process!of!systematically!finding,!appraising,!and!using!

contemporaneous!research!findings!as!the!basis!for!clinical!decisions”!is!called!!

Answer!!

!! !

Selected!Answer:! !c.!!!Systematic!review!!


Systematic!review!!!

!! !



Question!15!!

4!out!of!4!points!

! !

!

Considers!all!the!payoffs!for!each!alternative!!

Answer!! !!!

Selected!Answer:! !c.!!!Laplace!


Laplace!!

!! !

Question!16!!

4!out!of!4!points!

! !

!

The!essence!of!decision!making!is:!

Answer!! !!!


choosing!between!alternatives.!Correct!Answer:! !a.!!!

choosing!between!alternatives.!!

!! !


! !

!

Decision!analyses!always!require!comparison!of!at!least!two!clinical!

strategies.!ne!strategy!ought!to!contain!advantages!and!countervailing!

disadvantages.!!

Answer!!

!! !



!! !

Question!18!!

4!out!of!4!points!

! !

!

In!decision!tree!models!for!prognosis,!every!tree!contains!terminal!nodes!

that!represent!“subsequent!prognosis”!for!a!particular!combination!of!

patient!characteristics!and!events.!Answer!!

!! !



!! !


! !

!

Any!problem!that!can!be!represented!in!a!decision!table!can!also!be!

graphically!illustrated!in!a:!Answer!!

!! !


decision!tree.! !!!



Correct!Answer:! !c.!!!decision!tree.!

!


! !

!

All!the!following!decision!making!methods!are!deterministic!except:!!Answer!! !!!

Selected!Answer:! !d.!!!Markov!!


Markov!!!

!! !

Question!21!!

4!out!of!4!points!

! !

!

For!the!study!of!a!terminal!illness!such!as!HIV,!a!common!constraint!for!the!

Markov!process!is!that!state!transitions!are!irreversible!and!sequential.!!Answer!!

!! !



!! !


! !

!

DecisionOanalytic!models!must!be!sufficiently!complex!to!incorporate!the!

important!events!and!values,!yet!sufficiently!simple!to!be!understandable.!!Answer!!

!! !



!! !


! !

!

Which!of!the!following!is!(are)!types!of!decisionOmaking!environments?!

Answer!! !!!


All!of!the!above!


All!of!the!above!!

!! !

Question!24!!

4!out!of!4!points!

! !

!

The!number!of!patients!that!need!to!be!treated!with!the!technique!being!

investigated!to!prevent!an!unwanted!outcome.!

Answer!!!! !

Selected!Answer:! !b.!!!!! !



Number!needed!to!treat!

Correct!Answer:! !b.!!!Number!needed!to!treat!

!

Question!25!!


!

In!influence!diagram,!squares!or!rectangles!depict!!

Answer!! !!!


decision!nodes!!


decision!nodes!!!

!! !


! !

!

Conventional!decision!analysis!models!assumptions!include!all!the!following!

except:!

Answer!!!! !


Timing!of!events!is!important!


Timing!of!events!is!important!!

!! !

Question!27!!

4!out!of!4!points!

! !

!

A!point!!in!a!decision!tree!at!which!chance!determines!which!outcome!will!occur.!

Answer!!!! !


Chance!node!


Chance!node!!

!! !

Question!28!!

4!out!of!4!points!

! !

!

A!point!in!a!decision!tree!at!which!several!choices!are!possible.!Answer!! !!!


Decision!node!

Correct!Answer:! !d.!!!Decision!node!

!

!! !



Question!29!!

4!out!of!4!points!

! !

!

Decision!making!situations!can!be!categorized!along!a!scale!which!ranges!

from:!

Answer!!!! !


Certainty!to!risk!to!uncertainty!to!ambiguity!


Certainty!to!risk!to!uncertainty!to!ambiguity!!

!! !

Question!30!!

4!out!of!4!points!

! !

!

In!influence!diagram,!decision!nodes!are!depicted!as!!Answer!! !!!

Selected!Answer:! !b.!!!squares!or!rectangles!


squares!or!rectangles!!

!! !

Sunday,!April!21,!2013!8:11:22!AM!EDT!

!


! !

!

The!essence!of!decision!making!is:!

Answer!! !!!


choosing!between!alternatives.!


choosing!between!alternatives.!!

!! !

Question!2!!

4!out!of!4!points!

! !

!

A!point!in!a!decision!tree!at!which!several!choices!are!possible.!

Answer!! !!!


Decision!node!


Decision!node!!

!! !

Question!3!!

4!out!of!4!points!

! !

!

In!Markov!model,!all!events!of!interest!are!modeled!as!!!! !



Answer!!


transitions!from!one!state!to!another!!


transitions!from!one!state!to!another!!!

!! !

Question!4!!

4!out!of!4!points!

! !

!

The!criteria!of!Expected!Monetary!Value!is!used!for!making!decisions!under!

Answer!! !!!


all!of!the!above!


all!of!the!above!!

!! !


! !

!

All!the!following!are!components!of!a!decision!problem!except:!!

Answer!! !!!

Selected!Answer:! !c.!!!significance!level!!


significance!level!!!

!! !

Question!6!!


!

The!fact!that!the!data!are!censored!does!not!imply!that!only!intermediate!

endpoints!are!observed!or!that!complete!information!regarding!disease!states!is!unavailable!for!all!patients.!!!!

Answer!!

!! !



!! !

Question!7!!

4!out!of!4!points!

! !

!

Choosing!riskier!treatments!when!they!are!described!in!negative!(e.g.,!mortality)!rather!than!positive!(e.g.,!survival)!terms.!

Answer!!!! !


Framing!bias!


Framing!bias!!

!! !



Question!8!!

4!out!of!4!points!

! !

!

Providing!more!detail!of!an!event!increases!its!judged!probability.!

Answer!! !!!

Selected!Answer:! !c.!!!Description!bias!


Description!bias!!

!! !

Question!9!!

4!out!of!4!points!

! !

!

All!the!following!are!advantages!of!decision!trees!except:!

Answer!! !!!


High!accuracy!irrespective!of!the!nature!of!the!data!!!Correct!Answer:! !b.!!!

High!accuracy!irrespective!of!the!nature!of!the!data!!!!

!! !


! !

!

Decision!analyses!always!require!comparison!of!at!least!two!clinical!

strategies.!ne!strategy!ought!to!contain!advantages!and!countervailing!

disadvantages.!!

Answer!!

!! !



!! !

Question!11!!

4!out!of!4!points!

! !

!

A!state!of!a!Markov!model!may!be!defined!as!!

Answer!! !!!


a!or!b!


a!or!b!!

!! !

Question!12!!

4!out!of!4!points!

! !

!

A!point!!in!a!decision!tree!at!which!chance!determines!which!outcome!will!

occur.!

Answer!!!! !

Selected!Answer:! !b.!!!!! !



Chance!node!

Correct!Answer:! !b.!!!Chance!node!

!

Question!13!!


!

A!probability!model!that!predicts!the!conditional!probability!of!one!event!

given!the!occurrence!of!another!event!

Answer!!!! !


Bayes’!theorem!


Bayes’!theorem!!

!! !

Question!14!!


!

In!influence!diagram,!decision!nodes!are!depicted!as!!

Answer!! !!!


squares!or!rectangles!


squares!or!rectangles!!

!! !

Question!15!!

4!out!of!4!points!

! !

!

EMV!refers!to!Answer!! !!!


expected!monetary!value!!

Correct!Answer:! !d.!!!expected!monetary!value!!

!

!! !


! !

!

All!the!following!decision!making!methods!are!deterministic!except:!!

Answer!! !!!

Selected!Answer:! !c.!!!Markov!!


Markov!!!

!! !

Question!17!!



4!out!of!4!points!

! !

!

The!process!of!choosing!from!a!number!of!hypothetical!clinical!paradigms!by!

comparing!them!in!terms!of!modelObased!probabilistic!outcomes!is!often!

referred!to!as!!Answer!!

!! !


decision!analysis!!


decision!analysis!!!

!! !


! !

!

Markov!process!terminates!irrespective!of!the!nature!of!the!states.!

Answer!! !!!



!! !


! !

!

verestimating!probability!of!a!diagnosis!when!the!correct!diagnosis!is!

already!known!

Answer!!!! !

Selected!Answer:! !d.!!!Hindsight!error!


Hindsight!error!!

!! !


! !

!

A!decision!problem!is!characterized!by!!

Answer!! !!!


all!of!the!above!!


all!of!the!above!!!

!! !

Question!21!!

4!out!of!4!points!

! !

!

In!a!state!transition!diagram!each!state!is!represented!by!a!!

Answer!! !!!


circle!! !!!



Correct!Answer:! !e.!!!circle!!

!


! !

!

A!good!decision!always!implies!that!we!Answer!! !!!

Selected!Answer:! !a.!!!have!followed!a!logical!process.!


have!followed!a!logical!process.!!

!! !

Question!23!!

4!out!of!4!points!

! !

!

The!number!of!patients!that!need!to!be!treated!with!the!technique!being!

investigated!to!prevent!an!unwanted!outcome.!Answer!!

!! !


Number!needed!to!treat!


Number!needed!to!treat!!

!! !

Question!24!!

4!out!of!4!points!

! !

!

For!the!study!of!a!terminal!illness!such!as!HIV,!a!common!constraint!for!the!

Markov!process!is!that!state!transitions!are!irreversible!and!sequential.!!Answer!! !! !



!! !


! !

!

Any!problem!that!can!be!represented!in!a!decision!table!can!also!be!

graphically!illustrated!in!a:!

Answer!!!! !


decision!tree.!

Correct!Answer:! !c.!!!decision!tree.!

!

!! !

Question!26!!

4!out!of!4!points!

! !

!

Decision!analyses!!! !



Answer!!


a!and!b!


a!and!b!!

!! !

Question!27!!

4!out!of!4!points!

! !

!

A!commonly!used!representation!of!Markov!processes!

Answer!! !!!


State!transition!diagram!


State!transition!diagram!!

!! !


! !

!

Markov!models!are!particularly!useful!when!a!decision!problem!involves!a!

risk!that!is!!

Answer!!!! !


ongoing!over!time!!


ongoing!over!time!!!

!! !


! !

!

Markov!chain!is!a!special!type!of!Markov!process!in!which!the!transition!probabilities!are!constant!over!time.!

Answer!!!! !



!! !

Question!30!!

4!out!of!4!points!

! !

!

Decision!analysis!is!appropriate!for!events!that!reoccur!throughout!a!lifetime.!

Answer!!!! !



!! !

!



Question)1))

)

) )

)

Anything)that)increases)the)duration)of)the)disease)or)clinical)finding)in)a)patient)will)decrease)the)

chance)that)patient)will)be)identified)in)a)prevalence)study.)))

Answer)))) )

Correct)Answer:)) )False)

)

)) )

)

) )

)

Cumulative)incidence)is)the)appropriate)measure)to)use)in))

Answer)) )) )

Correct)Answer:) )a.)) )

80%)of)people)will)experience)back)pain)sometime)in)their)lifetime)

) )

)

)) )

Question)3))

)

) )

)

An)epidemic)curve)can)provide)information)on)the)following)characteristics)of)an)outbreak)except)

Answer)) )) )


Number)of)microorganisms)involved)

) )

)

)) )

Question)4))

) )

)

The)term,)simple)random)sample,)is)used)when)every)person)has)a)known)(not)necessarily)equal)

probability)of)being)selected.)

Answer)))) )




)

)) )

Question)5))

)

) )

)

Assume)a)population)of)1,000,000)people)of)who)100)are)sick)with)disease)X),)and)in)2008,)50)die)

from)the)disease.)The)case)fatality)rate=))

Answer)))) )

Correct)Answer:) )d.)))

50/100)

)

)) )

Question)6))

)

) )

)

In)the)study)of)an)outbreak)of)an)infectious)disease,)plotting)an)epidemic)curve)is)useful)because))

Answer)) )) )

Correct)Answer:) )e.)))

a)and)c)

) )

)

)) )

Question)7))

)

A)study)aimed)to)identify)modifiable)risk)factors)for)falling)in)older)people)with)mild)to)moderate)

dementia)recruited)179)subjects)(aged)over)65)years)from)outpatient)clinics)in)the)UK)(140)with)

dementia),)39)healthy)controls.)Fall)diaries)were)completed)prospectively)for)12)months.)Dementia)

participants)experienced)more)incident)falls)(9118/1000)personyears)than)controls)(1023/1000)

personyears.)The)design)of)the)study)is)known)as)

Answer))

)) )


prospective)cohort) )) )



) )

)

Question)8))

4)out)of)4)points)

))

)

A)study)was)conducted)to)assess)a)new)surgical)procedure)designed)to)reduce)the)incidence)of)

postoperative)complications.)The)incidence)of)complications)was)found)to)be)40%)in)25)patients)

having)the)new)procedure)and)60%)for)20)patients)having)the)old)procedure.)This)difference)is)not)

statistically)significant.)Thus,)it)may)be)concluded)that))

Answer))

)) )

Correct)

Answer:)

)d.)))

The)evidence)is)insufficient)to)demonstrate)that)the)new)procedure)is)effective)in)reducing)postoperative)complications.)

)

)) )

Question)9))

)

) )

)

When)epidemic)curve)shows)a)sharp)upward)slope)and)a)gradual)downward)slope,)the)type)of)

outbreak)can)be)identified)as))

Answer)))) )

Correct)Answer:) )b.)))

point)source)

)

)) )

Question)10))

)

) )

)

Is)incidence)or)prevalence)more)useful)in)planning)services)for)people)with)motor)neuron)disease)in)a)

community?)

Answer)))) )


Prevalence) )) )



) )

)

Question)11))

)

) )

)

The)incidence)of)sjogren's)syndrome)is)5/10,000)years,)and)the)prevalence)is)about)9/1000.)On)

average,)how)many)years)does)this)disease)last?))

Answer)))) )


18)

)

)) )

Question)12))

)

) )

)

A)highly)effective)new)drug)was)recently)discovered)for)treating)a)form)of)cancer)that)previously)had)

been)fatal.)Which)of)the)following)measures)would)NOT)be)affected)by)the)widespread)use)of)this)

new)drug?))

Answer))

)) )


Incidence)of)this)cancer))

) )

)

)) )

Question)13))

) )

)

The)difference)between)a)common)point)source)outbreak)and)a)propagated)outbreak)of)illness)is)that))

Answer)) )) )

Correct)

Answer:)

)d.)))

all)cases)in)a)common)point)source)outbreak)occur)within)one)incubation)period)of)

the)exposure))) )



) )

)

Question)14))

)

) )

)

The)proportion)of)people)having)a)disease)who)die)of)it)is)called)

Answer)) )) )

Correct)Answer:) )c.)))

case)fatality)rate)

)

)) )

Question)15))

)

) )

)

Which)of)the)following)is)characteristic)of)common)source)outbreak?)

Answer)) )) )


none)of)the)above))

)

)) )

Question)16))

)

) )

)

An)investigation)of)an)outbreak)of)diarrhea)revealed)that)the)proportion)of)cases)eating)in)restaurant)

A)was)85%,)in)restaurant)B)was)15%,)and)in)restaurant)C)was)55%,)and)the)proportion)consuming)

public)water)was)95%.)Which)of)the)following)statements)is)correct?)

Answer))

)) )


Similar)data)on)a)well)group)must)be)collected)to)reach)a)valid)conclusion.)

) )

)

)) )

Question)17))



)

) )) ) ) ) )

)

The)fraction)of)a)group)of)people)possessing)a)clinical)condition)or)outcome)at)a)single)point)in)

time)is)

Answer))) ) )


point)prevalence)

)

) ) )

Question)18))

)

) )

)

A)cardiologist)with)an)interest)in)preventive)medicine)wishes)to)know)the)proportion)of)seniors)living)

in)a)nursing)home)who)have)hypertension.)On)December)10th,)his)research)nurse)reviews)the)

medical)records)of)all)the)seniors)at)the)nursing)home,)interviews)all)the)seniors,)and)measures)their)

blood)pressure.)Each)senior)is)then)classified)as)having)hypertension)or)not)having)hypertension)on)

that)day.)What)measure)of)disease)frequency)best)describes)the)resulting)proportion?)

Answer))

)) )


Point)prevalence))

) )

)

)) )

Question)19))

) )

)

All)the)following)statements)about)prevalence)and)incidence)are)true)except))

Answer)) )) )


Prevalence)always)requires)a)duration)

) )

)

)) )

Question)20))



)

) )

)

Have)you)ever)had)health)condition?)The)data)generated)by)this)question)pertain)to))

Answer)) )) )


lifetime)prevalence)

) )

)

)) )

Question)21))

)

) )

)

With)measures)of)incidence,)time)is)assumed)to)be)instantaneous.)

Answer)) )) )

Correct)Answer:)) )True)

) )

)

)) )

Question)22))

)

) )

)

The)time)between)the)exposure)and)the)peak)of)the)epidemic)curve)represents))

Answer)) )) )


the)median)incubation)period)

) )

)

)) )

Question)23))

)

) )

)

Select)the)most)appropriate)explanation)for)prevalence)rate.)

)) )



Answer))

Correct)

Answer:)

)e.)))

the)number)of)patients)who)have)the)disease)at)a)particular)time,)divided)by)the)

population)at)risk)of)having)the)disease)at)that)time.))

) )

)

)) )

Question)24))

)

) )

)

A)researcher)is)interested)in)recording)the)number)of)individuals)in)a)particular)geographic)region)

who)have)a)common)cold)at)some)point)during)the)month)of)February)2007.)Which)of)the)following)

measures)of)morbidity)would)be)most)appropriate)in)answering)this)question?))

Answer))

)) )


Period)prevalence))

) )

)

)) )

Question)25))

)

) )

)

The)epidemic)curve)in)common)source)outbreak)

Answer)) )) )


has)irregular)peaks)that)reflect)the)timing)and)the)extent)of)exposure))

) )

)

)) )

Question)26))

4)out)of)4)points)

))



)





personyears.)The)exposure)in)this)cohort)is)

Answer))

)) )

Correct)Answer:) )b.))dementia))

)

)) )

Question)27))

4)out)of)4)points)

))

)

Outbreak)with)point)source)exposure)typically)shows)a)sharp)upward)slope)and)a)gradual)downward)

slope.))

Answer)))) )


) )

)

)) )

Question)28))

)

) )

)

The)term)pandemic)is)used)to)describe)a)

Answer)) )) )


widely)spread)disease)

) )

)

)) )

Question)29))

)

) )

)

Age) Annual)Incidence) Duration)

)) )



05) )))))6/1,000) 4.8))years)

616) )))))3/1,000) 10.7)years)

1744) )))))2/1,000) 13.0)years)

4564) )))))1/1,000) 33.0)years)

The)age)group)with)the)highest)prevalence)is)

Answer))


4564))

) ))

)) )

Question)30))

)

) )

)

The)strength)of)the)evidence)as)obtained)by)prevalence)studies)is))

Answer)) )) )


weak)

)

)) )

• Question 1

4 out of 4 points

Prevalence studies may raise promising hypotheses about risk, prognosis, treatment,

and prevention. Answer


Correct Answer:True

• Question 2

4 out of 4 points



The term, simple random sample, is used when every person has a known (notnecessarily equal) probability of being selected. Answer



• Question 3

4 out of 4 points

Select the most appropriate explanation for prevalence rate. Answer

Selected

Answer:a.

the number of patients who have the disease at a particular time, divided

by the population at risk of having the disease at that time.)

Correct

Answer:a.

the number of patients who have the disease at a particular time, divided

by the population at risk of having the disease at that time.)

• Question 4

4 out of 4 points

Prevalence studies are useful for estimating the pretest probability of disease beforediagnostic testing.Answer


Correct Answer:True

• Question 5

4 out of 4 points

A study was conducted to assess a new surgical procedure designed to reduce the

incidence of postoperative complications. The incidence of complications was foundto be 40% in 25 patients having the new procedure and 60% for 20 patients having the

old procedure. This difference is not statistically significant. Thus, it may beconcluded thatAnswer



Selected

Answer:b.

The evidence is insufficient to demonstrate that the new procedure iseffective in reducing postoperative complications.

Correct

Answer:

b.

The evidence is insufficient to demonstrate that the new procedure is

effective in reducing postoperative complications.

• Question 6

4 out of 4 points

The incidence of sjogren's syndrome is 5/10,000 years, and the prevalence is about 9/1000. On average,

how many years does this disease last?

Answer

Selected Answer:a.

18

Correct Answer:a.

18

• Question 7

4 out of 4 points

A study aimed to identify modifiable risk factors for falling in older people with mild to moderatedementia recruited 179 subjects (aged over 65 years) from outpatient clinics in the UK (140 with

dementia , 39 healthy controls). Fall diaries were completed prospectively for 12 months. Dementia

participants experienced more incident falls (9118/1000 person-years) than controls (1023/1000 person-

years). The incidence density ratio is approximately

Answer

Selected Answer:d.

9

Correct Answer:d.

9

• Question 8

4 out of 4 points

Outbreak with point source exposure typically shows a sharp upward slope and agradual downward slope.Answer




Correct Answer:True

• Question 9

0 out of 4 points

A group of people who have something in common at the beginning of follow-up

Answer

Selected Answer:b.

Cohort

Correct Answer:b.

Cohort

• Question 10

0 out of 4 points

Prevalence studies are useful for studies of cause and effect. Answer



• Question 11

4 out of 4 points

A cohort is a group of people who are a random sample of a defined population. Answer



• Question 12

4 out of 4 points

Cumulative incidence is the appropriate measure to use in

Answer



Selected Answer:a.

80% of people will experience back pain sometime in their lifetime

Correct Answer:a.


• Question 13

4 out of 4 points

The fraction of a group of people possessing a clinical condition or outcome at a single point in time is

Answer

Selected Answer:d.

point prevalence

Correct Answer: d.point prevalence

• Question 14

0 out of 4 points

Which)of)the)following)is)a)measure)of)the)strength)of)association?)

Answer

Selected Answer:

e.None of the above

Correct Answer:e.

None of the above

• Question 15

4 out of 4 points

Every measure of disease frequency necessarily contains some indication of time.Answer


Correct Answer:True

• Question 16



0 out of 4 points

In a probability sample, every individual in the population has an equal probability of

being selected.Answer


• Question 17

4 out of 4 points

All the following statements about prevalence and incidence are true except

Answer

Selected Answer:e.

Prevalence always requires a duration

Correct Answer:e.


• Question 18

0 out of 4 points

The)two)main)determinants)of)disease)prevalence)are)incidence)rate)and)duration)of)

illness.)

Answer


Correct Answer:True

• Question 19

0 out of 4 points

Which of the following statements regarding the measurement of health and disease in

a population is true? Answer

Correct

Answer:a.

a rate is the number of times an event has occurred during a certain timeinterval divided by the number of persons at risk during the same

interval.



• Question 20

4 out of 4 points

Anything that increases the duration of the disease or clinical finding in a patient will

decrease the chance that patient will be identified in a prevalence study.Answer



• Question 21

4 out of 4 points

Attack rate is a type of Answer

Selected Answer:a.

cumulative incidence

Correct Answer:a.

cumulative incidence

• Question 22

4 out of 4 points

Is incidence or prevalence more useful in understanding your risk of getting lung

cancer?

Answer

Selected Answer:a.

Incidence

Correct Answer:a.

Incidence



Question 23

4 out of 4 points

A sum of instances of a particular disease within the given population at a certain point in time is called

Answer

Selected Answer:b.

prevalence

Correct Answer:b.

prevalence

• Question 24

4 out of 4 points

Assume a population of 50,000 people of whom 50 are sick with disease ‘B’, and in

2010, 10 die from the disease. The case-fatality rate equals

Answer

Selected Answer:d.

0.2

Correct Answer:d.

0.2

•

• Question 25

0 out of 4 points

The time between the exposure and the peak of the epidemic curve representsAnswer

Correct Answer:b.

the median incubation period

•



Question 26

0 out of 4 points

The duration of disease x is 18 years, and the prevalence is about 9/1000. The incidence of the disease=

Answer

Selected Answer:c.

5/10,000

Correct Answer:c.

5/10,000

• Question 27

4 out of 4 points

Which of the following is characteristic of common source outbreak?

Answer

Selected Answer:e.

none of the above

Correct Answer:e.

none of the above

• Question 28

4 out of 4 points

The strength of the evidence as obtained by prevalence studies is

Answer

Selected Answer:c.

weak

Correct Answer:c.

weak



Question 29

0 out of 4 points

A study aimed to identify modifiable risk factors for falling in older people with mild to moderate

dementia recruited 179 subjects (aged over 65 years) from outpatient clinics in the UK (140 withdementia , 39 healthy controls). Fall diaries were completed prospectively for 12 months. Dementia


years). The exposure in this cohort is

Answer

Correct Answer:b. dementia

• Question 30

4 out of 4 points


dementia recruited 179 subjects (aged over 65 years) from outpatient clinics in the UK (140 with



years). The rate 9118/1000 person-years is called

Answer

Selected Answer:e.

incidence density

Correct Answer:e.

incidence density

• Question 1

4 out of 4 points

The strength of the evidence as obtained by prevalence studies is))

Answer)

Selected)Answer: )d.)))

weak

Correct)Answer: )d.)))

weak



• Question 2

4 out of 4 points

Is incidence or prevalence more useful in planning services for people with motor

neuron disease in a community?

Answer)

Selected)Answer: )a.)))

Prevalence

Correct)Answer: )a.)))

Prevalence

• Question 3

4 out of 4 points

The)incidence)of)sjogren's)syndrome)is)5/10,000)years,)and)the)prevalence)is)about)9/1000.)

On)average,)how)many)years)does)this)disease)last?))

Answer)

Selected)Answer: )a.)))

18


18



Question 4

The)calculated)risk)of)acquiring)a)new)state)(e.g.)becoming)sick)within)a)certain)timeframe,)which)is)

best)represented)as)a)rate)with)a)denominator)is)known)as)

Answer)

Correct)Answer: )c.)))

incidence

• Question 5

4 out of 4 points

Outbreak with point source exposure typically shows a sharp upward slope and a

gradual downward slope. )

Answer)

Selected)Answer:) )True

Correct)Answer:) )True

• Question 6

4 out of 4 points

The term pandemic is used to describe a

Answer)

Selected)Answer: )b.)))

widely spread disease

Correct)Answer: )b.)))

widely spread disease



• Question 7

4 out of 4 points

Prevalence studies may raise promising hypotheses about risk, prognosis, treatment,

and prevention.)

Answer)



• Question 8

100 males and 100 females who were not infected by malaria at Week 0 were followed up for 25 weeks

and weekly checked for malaria infection. The result was shown in this graph. What does the graph

indicate?

Answer)


Malaria incidence was higher in female than in male.

Question 9

4 out of 4 points

Outbreak with propagated exposure can last longer than common source outbreaks. )

Answer)




Question 10

4 out of 4 points

The)epidemic)curve)in)common)source)outbreak)

Answer)

Selected)Answer: )d.)))

has)irregular)peaks)that)reflect)the)timing)and)the)extent)of)exposure)


has)irregular)peaks)that)reflect)the)timing)and)the)extent)of)exposure)

• Question 11

4 out of 4 points

A group of people who have something in common at the beginning of follow-up))

Answer)

Correct)Answer: )b.))Cohort)

Question 12

Point source outbreak is spread from person to person.)

Answer)

Correct)Answer:) )False



• Question 13

4 out of 4 points

In)calculating)cumulative)incidence,)the)denominator)is)the)total)population)(at)risk)or)

not)in)the)study. )

Answer)

Selected)Answer:) )False


• Question 14

4 out of 4 points

A)measure)describes)cases)that)were)present)at)any)time)during)a)specified)period)of)time)is)called)

Answer)


period)prevalence

Question 15

Incidence)density)is)the)appropriate)measure)to)use)in))

Answer)

Correct)Answer: )e.)))

About)2%)of)the)U.S.)workforce)is)compensated)for)back)injuries)each)year



• Question 16

4 out of 4 points

Attack rate is a type of point prevalence. )

Answer)



• Question 17

4 out of 4 points

Have)you)ever)had)health)condition?)The)data)generated)by)this)question)pertain)to))

Answer)

Selected)Answer: )e.)))

lifetime)prevalence

Correct)Answer: )e.)))

lifetime)prevalence

• Question 18

4 out of 4 points

A cohort is a group of people who are a random sample of a defined population.)

Answer)




• Question 19

0 out of 4 points





personyears.)The)design)of)the)study)is)known)as)

Answer)

Correct)Answer: )a.))prospective)cohort)

Question 20

Age Annual Incidence Duration

0-5 6/1,000 4.8 years

6-16 3/1,000 10.7 years

17-44 2/1,000 13.0 years

45-64 1/1,000 33.0 years

The prevalence of the disease in age group ‘6-16’ isAnswer)


32/1,000



Question 21

0 out of 4 points

A)retrospective)cohort)study)was)conducted)from)1998)to)2006)to)examine)the)value)of)combining)

fasting)plasma)glucose)(FPG)and)glycated)haemoglobin)(HbA1c)as)a)predictor)of)diabetes.)There)

were)368)cases)in)10,042)persons)(55,884)personyears.)The)incidence)density)is)

Answer)

Correct)Answer: )b.))368/55,884)

Question 22

0 out of 4 points

Period)prevalence)is)the)appropriate)measure)to)use)in))

Answer)


15%45%)of)adults)have)back)pain)at)some)time)in)any)year

• Question 23

4 out of 4 points

The number of people diagnosed with disease A each year will double. The death rates from

disease A continue to fall about 1 percent. The prevalence of disease A will Answer)


increase



Question 24

4 out of 4 points

Cross-sectional studies are useful for studies of chronic diseases. )

Answer)


• Question 25

0 out of 4 points

A group of 50 people are exposed to virus “A”. Of those 50 people, 9 develop a mildinfection, 10 become seriously ill, and 3 die. The attack rate of virus “A” in the population

would be: Answer)


22/50



Question 26

4 out of 4 points

Differentiation between a point-source epidemic and a progressive (propagated) epidemic is

made by))

Answer)

Correct)Answer: )d.)) plotting the distribution of cases by time onset)

• Question 27

0 out of 4 points

Assume a population of 50,000 people of whom 50 are sick with disease ‘B’, and in2010, 10 die from the disease. The mortality rate equals

Answer)


0.001

• Question 28

4 out of 4 points

Age Annual Incidence Duration

0-5 6/1,000 4.8 years

6-16 3/1,000 10.7 years

17-44 2/1,000 13.0 years

45-64 1/1,000 33.0 years

The age group with the highest prevalence is

Answer)




45-64)

Question 29

4 out of 4 points

A)sum)of)instances)of)a)particular)disease)within)the)given)population)at)a)certain)point)in)

time)is)called)

Answer)


prevalence

• Question 30

4 out of 4 points

The term, simple random sample, is used when every person has a known (not

necessarily equal) probability of being selected.)

Answer)



Question)1))

4)out)of)4)points)

) )

)

A)cardiologist)with)an)interest)in)preventive)medicine)wishes)to)know)the)proportion)of)seniors)

living)in)a)nursing)home)who)have)hypertension.)On)December)10th,)his)research)nurse)reviews)

the)medical)records)of)all)the)seniors)at)the)nursing)home,)interviews)all)the)seniors,)and)

measures)their)blood)pressure.)Each)senior)is)then)classified)as)having)hypertension)or)not)

)) )



having)hypertension)on)that)day.)What)measure)of)disease)frequency)best)describes)the)

resulting)proportion?)

Answer))

Selected)Answer:) )e.)))

Point)prevalence))


Point)prevalence))

)

)) )

Question)2))

4)out)of)4)points)

) )

)

Assume)a)population)of)50,000)people)of)whom)50)are)sick)with)disease)‘B’,)and)in)2010,)10)die)

from)the)disease.))The)mortality)rate)equals)

Answer)))) )


0.001)


0.001)

)

)) )

Question)3))

4)out)of)4)points)

) )

)


05) )))))6/1,000) 4.8))years)

616) )))))3/1,000) 10.7)years)

1744) )))))2/1,000) 13.0)years)

4564) )))))1/1,000) 33.0)years)

The)prevalence)of)the)disease)in)age)group)‘616’)is))

)) )



Answer))

Selected)Answer:) )a.)))

32/1,000)

Correct)Answer:) )a.)))

32/1,000)

)

)) )

Question)4))

4)out)of)4)points)

) )

)

100)males)and)100)females)who)were)not)infected)by)malaria)at)Week)0)were)followed)up)for)25)

weeks)and)weekly)checked)for)malaria)infection.)The)result)was)shown)in)this)graph.)What)does)the)

graph)indicate?)

• Question 1

4 out of 4 points

A group of 50 people are exposed to virus “A”. Of those 50 people, 9 develop a

mild infection, 10 become seriously ill, and 3 die. The attack rate of virus “A” in the population would be: Answer

Selected Answer:b.

22/50

Correct Answer:b.

22/50

• Question 2

4 out of 4 points




participants experienced more incident falls (9118/1000 person-years) than controls (1023/1000

person-years). The rate 9118/1000 person-years is called

Answer

Selected Answer:e.

) ))



incidence density

Correct Answer:e.

incidence density

• Question 3

4 out of 4 points

All the following statements about prevalence and incidence are true except

Answer

Selected Answer:e.


Correct Answer:e.


• Question 4

4 out of 4 points

A study was conducted to assess a new surgical procedure designed to reduce the

incidence of postoperative complications. The incidence of complications wasfound to be 40% in 25 patients having the new procedure and 60% for 20 patients

having the old procedure. This difference is not statistically significant. Thus, it may

be concluded thatAnswer

Selected

Answer:a.



Correct

Answer:a.



• Question 5

4 out of 4 points

Differentiation between a point-source epidemic and a progressive (propagated)epidemic is made by

Answer



Selected Answer:d.

plotting the distribution of cases by time onset

Correct Answer:d.

plotting the distribution of cases by time onset

• Question 6

4 out of 4 points

The risk of acquiring a disease is measured by

Answer

Selected Answer:e.

incidence rate

Correct Answer:e.

incidence rate

• Question 7

4 out of 4 points

The incidence of new cases of diabetes in a population is 2 per 1000 people per year

and the prevalence of diabetes in a population is 7 percent. The duration of the

disease equalsAnswer

Selected Answer:d.

35

Correct Answer:d.

35

• Question 8

4 out of 4 points

Prevalence studies are useful for studies of cause and effect. Answer





• Question 9

4 out of 4 points

Cumulative incidence is the appropriate measure to use in

Answer

Selected Answer:a.


Correct Answer:a.


• Question 10

4 out of 4 points




participants experienced more incident falls (9118/1000 person-years) than controls (1023/1000

person-years). The incidence density ratio is approximately

Answer

Selected Answer:d.

9

Correct Answer: d.9

• Question 11

0 out of 4 points

An epidemiologist is interested in the incidence of hepatitis A infection among a population of 1000

students who are known to be at risk for this disease. 500 students were followed for 1 year and

among these students there were 40 cases of hepatitis A. Owing to a school zone change, the

remaining 500 students could only be followed for 6 months and among these students there were 35

cases of hepatitis What is the incidence density of hepatitis A from this study?Answer

Selected Answer:c.

75 per 500 per year

Correct Answer:b.

11 per 100 per year



• Question 12

4 out of 4 points

The calculated risk of acquiring a new state (e.g. becoming sick) within a certain timeframe, which is

best represented as a rate with a denominator is known as

Answer

Selected Answer:c.

incidence

Correct Answer:c.

incidence

• Question 13

4 out of 4 points

The difference between a common point source outbreak and a propagated outbreak

of illness is that Answer

Selected

Answer:e.

all cases in a common point source outbreak occur within oneincubation period of the exposure

Correct

Answer: e.all cases in a common point source outbreak occur within oneincubation period of the exposure

• Question 14

4 out of 4 points

The incidence of rheumatoid arthritis is 30/100,000 years, and the prevalence is about 1/100. On

average, how many years does this disease last?

Answer

Selected Answer:e.

33

Correct Answer:e.

33



• Question 15

4 out of 4 points

In a probability sample, every individual in the population has an equal probabilityof being selected.Answer



• Question 16

4 out of 4 points

With measures of incidence, time is assumed to be instantaneous. Answer



• Question 17

4 out of 4 points

The proportion of patients who suffer a complication of a disease or its treatment is known as

complication

Answer

Selected Answer:b.

rate

Correct Answer:b.

rate

• Question 18

4 out of 4 points

100 males and 100 females who were not infected by malaria at Week 0 were followed up for

25 weeks and weekly checked for malaria infection. The result was shown in this graph.

What does the graph indicate?



Answer

Selected Answer:c.


Correct Answer:c.


• Question 19

4 out of 4 points

A cardiologist with an interest in preventive medicine wishes to know the proportion of seniors

living in a nursing home who have hypertension. On December 10th, his research nurse reviews the

medical records of all the seniors at the nursing home, interviews all the seniors, and measures theirblood pressure. Each senior is then classified as having hypertension or not having hypertension on

that day. What measure of disease frequency best describes the resulting proportion?

Answer

Selected Answer:e.

Point prevalence

Correct Answer:e.

Point prevalence

• Question 20

4 out of 4 points

A group of people who have something in common at the beginning of follow-up

Answer

Selected Answer:b.

Cohort

Correct Answer:b.

Cohort

• Question 21

4 out of 4 points

Case fatality rate for a given disease refers toAnswer



Selected Answer:c.

the percentage of deaths among cases of the disease

Correct Answer:c.

the percentage of deaths among cases of the disease

• Question 22

4 out of 4 points

A sum of instances of a particular disease within the given population at a certain point in time is

called

Answer

Selected Answer:b.

prevalence

Correct Answer:b.

prevalence

• Question 23

4 out of 4 points

The proportion of people having a disease who die of it is called

Answer

Selected Answer:c.

case fatality rate

Correct Answer:c.

case fatality rate

• Question 24

4 out of 4 points

The fraction of a group of people possessing a clinical condition or outcome at a single point in time

is

Answer

Selected Answer:d.

point prevalence

Correct Answer:d.



point prevalence

• Question 25

4 out of 4 points

Have you ever had health condition? The data generated by this question pertain to

Answer

Selected Answer:e.

lifetime prevalence

Correct Answer:e.

lifetime prevalence

• Question 26

4 out of 4 points

Prevalence studies are useful for studies that arise and resolve rapidly. Answer



•Question 27

4 out of 4 points

The actual number of people affected by a condition in a year can be estimated

using

Answer

Selected Answer:a.

Prevalence

Correct Answer:

a.Prevalence

• Question 28

4 out of 4 points



A highly effective new drug was recently discovered for treating a form of cancer that

previously had been fatal. Which of the following measures would NOT be affected by

the widespread use of this new drug?Answer

Selected Answer:b.

Incidence of this cancer

Correct Answer:b.

Incidence of this cancer

• Question 29

4 out of 4 points

Age Annual Incidence Duration 0-5 6/1,000 4.8 years

6-16 3/1,000 10.7 years

17-44 2/1,000 13.0 years

45-64 1/1,000 33.0 years

The prevalence of the disease in age group ‘6-16’ isAnswer

Selected Answer:a.

32/1,000

Correct Answer:a.

32/1,000

• Question 30

4 out of 4 points

In#calculating#cumulative#incidence,#the#denominator#is#the#total#population#(at#

risk#or#not)#in#the#study. Answer

Selected Answer:

FalseCorrect Answer:

False

)



Answer))

Selected)Answer:) )b.)))

Malaria)incidence)was)higher)in)female)than)in)male.))


Malaria)incidence)was)higher)in)female)than)in)male.))

)

) ))

Question)5))

4)out)of)4)points)

) )

)

Which)of)the)following)is)characteristic)of)common)source)outbreak?)

Answer)) )) )


none)of)the)above))


none)of)the)above))

)

)) )

Question)6))

4)out)of)4)points)

) )

)

Select)the)most)appropriate)explanation)for)prevalence)rate.)

Answer)) )) )

Selected)

Answer:)

)a.)))

the)number)of)patients)who)have)the)disease)at)a)particular)time,)divided)by)

the)population)at)risk)of)having)the)disease)at)that)time.))

Correct)

Answer:)

)a.)))

the)number)of)patients)who)have)the)disease)at)a)particular)time,)divided)by)

the)population)at)risk)of)having)the)disease)at)that)time.))

)

)) )



Question)7))

4)out)of)4)points)

) )

)

The)incidence)of)sjogren's)syndrome)is)5/10,000)years,)and)the)prevalence)is)about)9/1000.)On)

average,)how)many)years)does)this)disease)last?))

Answer)))) )


18)


18)

)

)) )

Question)8))

4)out)of)4)points)

) )

)

The)difference)between)a)common)point)source)outbreak)and)a)propagated)outbreak)of)illness)

is)that))

Answer)))) )

Selected)

Answer:)

)c.)))

all)cases)in)a)common)point)source)outbreak)occur)within)one)incubation)

period)of)the)exposure)

Correct)

Answer:)

)c.)))

all)cases)in)a)common)point)source)outbreak)occur)within)one)incubation)

period)of)the)exposure)

)

)) )

Question)9))

4)out)of)4)points)

) )

)

A)group)of)people)who)have)something)in)common)at)the)beginning)of)followup))

Answer)) )) )




Cohort)


Cohort)

)

)) )

Question)10))

4)out)of)4)points)

) )

)

The)calculated)risk)of)acquiring)a)new)state)(e.g.)becoming)sick)within)a)certain)timeframe,)

which)is)best)represented)as)a)rate)with)a)denominator)is)known)as)

Answer)))) )

Selected)Answer:) )c.)))

incidence)


incidence)

)

)) )

Question)11))

4)out)of)4)points)

) )

)

A)study)aimed)to)identify)modifiable)risk)factors)for)falling)in)older)people)with)mild)to)

moderate)dementia)recruited)179)subjects)(aged)over)65)years)from)outpatient)clinics)in)the)

UK)(140)with)dementia),)39)healthy)controls.)Fall)diaries)were)completed)prospectively)for)12)

months.)Dementia)participants)experienced)more)incident)falls)(9118/1000)personyears)than)

controls)(1023/1000)personyears.)The)exposure)in)this)cohort)is)

Answer))

)) )

Selected)Answer:) )b.))dementia))

Correct)Answer:) )b.))dementia))

)

)) )

Question)12))

4)out)of)4)points)



) )

)

Crosssectional)studies)are)useful)for)studies)of)chronic)diseases.)))

Answer)) )) )

Selected)Answer:)) )True)


)

)) )

Question)13))

4)out)of)4)points)

) )

)

Case)fatality)rate)for)a)given)disease)refers)to))

Answer)) )) )


the)percentage)of)deaths)among)cases)of)the)disease)


the)percentage)of)deaths)among)cases)of)the)disease)

)

)) )

Question)14))

0)out)of)4)points)

) )

)

Point)prevalence)is)the)appropriate)measure)to)use)in))

Answer)) )) )


31)million)American)have)low)back)pain)at)any)given)time)


30%)of)adults)have)low)back)pain)at)any)given)time)

)

)) )

Question)15))

4)out)of)4)points)

) )



)

The)strength)of)the)evidence)as)obtained)by)prevalence)studies)is))

Answer)) )) )


weak)


weak)

)

)) )

Question)16))

4)out)of)4)points)

) )

)

Period)prevalence)is)the)appropriate)measure)to)use)in))

Answer)) )) )


15%45%)of)adults)have)back)pain)at)some)time)in)any)year)


15%45%)of)adults)have)back)pain)at)some)time)in)any)year)

)

)) )

Question)17))

4)out)of)4)points)

) )

)

Outbreak)with)point)source)exposure)typically)shows)a)sharp)upward)slope)and)a)gradual)

downward)slope.))

Answer)))) )



)

)) )

Question)18))

4)out)of)4)points)

) )



)


05) )))))6/1,000) 4.8))years)

616) )))))3/1,000) 10.7)years)

1744) )))))2/1,000) 13.0)years)

4564) )))))1/1,000) 33.0)years)

The)age)group)with)the)highest)prevalence)is)

Answer))

)) )


4564))


4564))

)

)) )

Question)19))

4)out)of)4)points)

) )

)


moderate)dementia)recruited)179)subjects)(aged)over)65)years)from)outpatient)clinics)in)the)UK)(140)with)dementia),)39)healthy)controls.)Fall)diaries)were)completed)prospectively)for)12)


controls)(1023/1000)personyears.)The)design)of)the)study)is)known)as)

Answer))

)) )


prospective)cohort)


prospective)cohort)

)

)) )

Question)20))

4)out)of)4)points)



) )

)

Incidence)density)is)the)appropriate)measure)to)use)in))

Answer)) )) )


About)2%)of)the)U.S.)workforce)is)compensated)for)back)injuries)each)year)


About)2%)of)the)U.S.)workforce)is)compensated)for)back)injuries)each)year)

)

)) )

Question)21))

4)out)of)4)points)

) )

)


moderate)dementia)recruited)179)subjects)(aged)over)65)years)from)outpatient)clinics)in)the)

UK)(140)with)dementia),)39)healthy)controls.)Fall)diaries)were)completed)prospectively)for)12)


controls)(1023/1000)personyears.)The)rate)9118/1000)personyears)is)called)

Answer))

)) )


incidence)density)


incidence)density)

)

)) )

Question)22))

4)out)of)4)points)

) )

)

Is)incidence)or)prevalence)more)useful)in)planning)services)for)people)with)motor)neuron)

disease)in)a)community?)

Answer)))) )


)) )



Prevalence)


Prevalence)

)

Question)23))

4)out)of)4)points)

) )

)

A)study)was)conducted)to)assess)a)new)surgical)procedure)designed)to)reduce)the)incidence)of)

postoperative)complications.)The)incidence)of)complications)was)found)to)be)40%)in)25)

patients)having)the)new)procedure)and)60%)for)20)patients)having)the)old)procedure.)This)

difference)is)not)statistically)significant.)Thus,)it)may)be)concluded)that))

Answer))

)) )

Selected)

Answer:)

)e.)))

The)evidence)is)insufficient)to)demonstrate)that)the)new)procedure)is)

effective)in)reducing)postoperative)complications.)

Correct)

Answer:)

)e.)))

The)evidence)is)insufficient)to)demonstrate)that)the)new)procedure)is)

effective)in)reducing)postoperative)complications.)

)

)) )

Question)24))

4)out)of)4)points)

) )

)

A)sum)of)instances)of)a)particular)disease)within)the)given)population)at)a)certain)point)in)time)

is)called)

Answer)))) )


prevalence)


prevalence)

)

)) )



Question)25))

4)out)of)4)points)

) )

)

Differentiation)between)a)pointsource)epidemic)and)a)progressive)(propagated)epidemic)is)

made)by))

Answer)))) )

Selected)Answer:) )d.)))

plotting)the)distribution)of)cases)by)time)onset)


plotting)the)distribution)of)cases)by)time)onset)

)

)) )

Question)26))

4)out)of)4)points)

) )

)

In)1997,)the)JCHBP)changed)its)definition)of)hypertension;)the)old)definition)called)for)the)

treatment)of)people)with)SBP)>=)160,)while)the)new)definition)would)treat)people)with)SBP)>=)

140.)Changing)the)definition)of)hypertention)resulted)in))

Answer))

)) )


an)increase)in)prevalence)of)hypertension)


an)increase)in)prevalence)of)hypertension)

)

)) )

Question)27))

4)out)of)4)points)

) )

)

Assume)a)population)of)1,000,000)people)of)who)100)are)sick)with)disease)X),)and)in)2008,)50)

die)from)the)disease.)The)case)fatality)rate=))

Answer)))) )




50/100)


50/100)

)

)) )

Question)28))

4)out)of)4)points)

) )

)

A)retrospective)cohort)study)was)conducted)from)1998)to)2006)to)examine)the)value)of)

combining)fasting)plasma)glucose)(FPG)and)glycated)haemoglobin)(HbA1c)as)a)predictor)of)

diabetes.)There)were)368)cases)in)10,042)persons)(55,884)personyears.)The)incidence)density)

is)

Answer))

)) )


368/55,884)


368/55,884)

)

)) )

Question)29))

4)out)of)4)points)

) )

)

The)actual)number)of)people)affected)by)a)condition)in)a)year)can)be)estimated)using))

Answer)) )) )


Prevalence)


Prevalence)

)

)) )

Question)30))



4)out)of)4)points)

) )

)

When)epidemic)curve)shows)a)sharp)upward)slope)and)a)gradual)downward)slope,)the)type)of)

outbreak)can)be)identified)as))

Answer))

)) )


point)source)


point)source)

)

)) )


If we assume that the relative risk reduction associated with statin treatment is 33%, in

patients with an initial risk of 30% the absolute risk will be reduced from 30% to Answer

Selected Answer:c.

20%

Correct Answer:c.

20%


Case-control studies would be useful for answering all the following questions exceptAnswer

Selected

Answer:d.

What is the incidence of impotence following the use of cholesterol-

lowering drugs?

Correct

Answer:d.

What is the incidence of impotence following the use of cholesterol-

lowering drugs?


In the British doctors study, over 40 years of follow up, the annual mortality rate fromCHD was 572 per 100 000 in non-smokers, and 892 per 100 000 in smokers. For lung

cancer the figures were 14 and 209, respectively. Therefore for an individual, smokingwas much more likely to result in death from lung cancer than from CHD.Answer






In the British doctors study, over 40 years of follow up, the annual mortality rate fromCHD was 572 per 100 000 in non-smokers, and 892 per 100 000 in smokers. The

relative risk Answer

Selected Answer:d.

1.6

Correct Answer:d.

1.6

• Question 5

4 out of 4 points

Measures of absolute, attributable, and relative risks are less frequently encountered inthe clinical literature than are measures of population risk.Answer




All the followings are disadvantages of cross-sectional studies exceptAnswer

Selected

Answer: b.

Always less generalizable than cohort due to the use of populationbased samples, instead of convenient samples.

Correct

Answer: b.

Always less generalizable than cohort due to the use of populationbased samples, instead of convenient samples.


In the British doctors study, over 40 years of follow up, the annual mortality rate fromCHD was 572 per 100 000 in non-smokers, and 892 per 100 000 in smokers. For lungcancer the figures were 14 and 209, respectively. The attributable risk of CHD related

to smoking Answer

Selected Answer:a.

320 per 100 000



Correct Answer:a.

320 per 100 000


Smoke

Develop CHD

Total Yes No

Yes 30 70 100

No 30 270 300

Total 60 240 400

Incidece of CHD=

Answer

Selected Answer:e.

0.1

Correct Answer: b.

0.15


The effect of most risk factors in human cannot be studied with experimental studies.Answer


Correct Answer:True


The incidence of disease A among smokers is 6/10000 and is (5 / 10000) among

nonsmokers. The relative risk for smoking=Answer

Selected Answer:c.

1.2

Correct Answer:c.

1.2


A design well suited for studying symptoms and signs of a disease isAnswer

Selected Answer:a.

case series



Correct Answer:a.

case series


Smoke

Develop CHD

Total

Yes No

Yes 10 90 100

No 5 95 100

Total 15 185 200

Risk among smokers=

Answer

Selected Answer:

0.1

Correct Answer:

0.1


Public health officials believe that they could prevent 10 cases of Hepatitis C per 5,000 interns over a 10-year period by preventing all of their needle stick injuries.

Select the best answer:Answer

Selected

Answer:d.

This is the incidence rate of Hepatitis C in interns with needle stick

injuries.

Correct

Answer:a.

This is the attributable risk of Hepatitis C due to needle stick injuriesin interns.


A heavy smoker has about 50% chance of getting lung cancer in the next 10 years.

Answer




The excess incidence of disease in a community that is associated with a risk factor Answer



Selected Answer:a.

population attributable risk

Correct Answer:a.



The presence of a strong risk factor indicates that an individual is very likely to get thediseaseAnswer

Selected Answer:a.

False

Correct Answer:a.

False


If we assume that the relative risk reduction associated with certain treatment is 10%,

in patients with an initial risk of 20% the absolute risk will be reduced from 20% to Answer

Selected Answer: b.

18%

Correct Answer: b.

18%


The excess incidence of disease in a community that is associated with a risk factor Answer

Selected Answer:a.


Correct Answer:a.



Most studies of risk are observational studies and are either cross-sectional or caseseriesAnswer

Selected Answer: b.

False



Correct Answer: b.

False


Smoke

Develop CHD

Total

Yes No

Yes 10 90 100

No 5 95 100

Total 15 185 200

Risk among nonsmokers=

Answer

Selected Answer:a.

0.05

Correct Answer:a.

0.05


All the following statements are true exceptAnswer

Selected

Answer:d.

If a risk factor is a cause of a disease , removing it is not necessary to prevent the disease.

Correct

Answer:d.



A measure suitable for policy decision Answer

Selected Answer:

a.attributable risk

Correct Answer:a.

attributable risk




The odds ratio (OR) is the

Answer

Selected

Answer:a.

ratio of the odds of the exposure in the disease group, to the odds of thedisease in the unexposed group.

Correct

Answer:c.

ratio of the odds of the disease in the group exposed to the factor, to theodds of the disease in the unexposed group.


Population attributable risk is the excess incidence of disease in a community that is

associated with a risk factor.Answer


Correct Answer:True


The prevalence of a disease at a point in time is a function of incidence and duration. Answer


Correct Answer:True


In a series of 1000 women with breast cancer, 32 were pregnant. From this we can

conclude: Answer

Selected

Answer:c.

In this particular series of women with breast cancer, 3.2% were

pregnant

Correct Answer:c.

In this particular series of women with breast cancer, 3.2% were pregnant


Incidence studies are also called Answer

Selected Answer:e.

a and b



Correct Answer:e.

a and b


All of the following statements are true about both prospective and retrospectivecohort studies except:Answer

Selected Answer:d.

They allow investigators to decide beforehand what data to collect

Correct Answer:d.

They allow investigators to decide beforehand what data to collect


The number of times that exposed persons are more likely to get the disease relative tononexposed is calledAnswer

Selected Answer: b.

relative risk

Correct Answer: b.

relative risk


If we assume that the relative risk reduction associated with certain treatment is 50%,in patients with an initial risk of 50% the absolute risk will be reduced from 50% to

Answer

Selected Answer:a.

25%

Correct Answer:a.

25%

)




Ideally, no association should be accepted as causal until it has been repeatedlyandindependently confirmed.Answer


Correct Answer:True


The lack of scientific plausibility should deter us from inferring causality.Answer



• Question 3

0 out of 4 points

Which of the following factors is necassary to have coronary artery disease?Answer

Selected Answer:c.

cigarette smoking and heridity

Correct Answer:e.

none of the above


Demonstrating a dose response relationshipAnswer

Selected Answer:c.

is strong evidence for cause

Correct Answer:d.

both a and b


In the formula, "If x happens, then y always happens," x is a __________ condition for y. Answer

Selected Answer: b.

Necessary

Correct Answer:a.



Necessary


For high RR estimates (say ≥5.0) small numbers may be sufficient to set

confidence limits that exclude 1.0.Answer


Correct Answer:True


Confounding can either suppress or inflate an association. Answer




A factor which is indispensible and must have occurred if a specifiable state of

affairs has occurred is a __________ condition. Answer

Selected Answer:c.

Contradictory

Correct Answer:d.

Necessary


Which of the following would strengthen your sense that cell phones are or arenot related to brain tumors?Answer

Selected Answer:d.

All of the above

Correct Answer:d.

All of the above


Studies in which exposure to a risk factor is characterized by the averageexposure of the group to which individuals belong are calledAnswer




Correct Answer: b.

ecological

• Question 11 0 out of 4 points

Which of the following criteria of causality is satisfied ; when several studies,conducted at different times in different settings and with different kinds of

patients, all come to the same conclusion?Answer

Selected Answer:d.

Specificity

Correct Answer:e.

Consistency


Exposure to benzene is __________ for causing leukemia. Answer

Selected Answer:c.

Sufficient

Correct Answer:c.

Sufficient


Coronary artery disease has multiple causes, includingAnswer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 14

4 out of 4 points

Lack of temporal sequence is powerful evidence against causeAnswer

Selected Answer:a.

true

Correct Answer:a.



true


The suspected cause and the effect must be associated if they are to be

considered as causally related.Answer

Selected Answer: b.

false

Correct Answer:a.

true


Many studies conducted in various geographic regions and with differing study

methods report areduced rate of infection associated with implementation of hygiene intervention programs. Which causality criterion is satisfied here?

Answer

Selected Answer: b.

Analogy

Correct Answer:a.

Consistency


When more than one cause acts together, the resulting risk may be greater or less than would be expected by simply combining the effects of the separatecauses. This phenomenon is known asAnswer

Selected Answer: b.

biologic plausibility

Correct Answer:d.

interaction

• Question 18

4 out of 4 points

Unrecognized bias could account for small relative risks but is unlikely to

result in large ones.Answer

Selected Answer:a.

true



Correct Answer:a.

true


OR is defined as the odds of Answer

Selected

Answer:a.

exposure among the diseased as compared with those of thenon-diseased.

Correct

Answer:d.

disease among the exposed as compared with those of the

unexposed.

• Question 20

0 out of 4 points

Radiation exposure is a __________ exposure for causing leukemia. Answer

Selected Answer:a.

Necessary

Correct Answer:c.

Sufficient


Does 1 cause have a single effect? Which causality criterion is referred to inthis question?

Answer

Selected Answer: b.

Coherence

Correct Answer:c.

Specificity


The confidence interval provides information on the precision of the point

estimate (RR, IDR, or OR) and the magnitude of the association.Answer


Correct Answer:True




The presence or absence of a dose-response effect may not necessarily beevidence of causality. Answer




The main bias afflicting ecological studies isAnswer

Selected Answer:c.

ecological fallacy

Correct Answer:c.

ecological fallacy


Antagonism occurs when the joint effect is less than the sum of the effects of individual causes.Answer

Selected Answer:a.

true

Correct Answer:a.

true


An alternative to estimation of the relative risk (RR) and its confidence

interval (CI) is to estimate

Answer

Selected Answer:c.

Clinical significance

Correct Answer:e.

Statistical significance


In both follow-up and case-control studies the single most important

determinant of power is

Answer

Selected Answer:c.



alpha level

Correct Answer:a.

number of exposed cases


The OR, generated when the study design used is

Answer

Selected Answer:d.

Cohort

Correct Answer:c.

Case-control


The further one departs from randomized trials, the more the research design

protects against possible biases.Answer

Selected Answer: b.

false

Correct Answer: b.

false

• Question 30

4 out of 4 points

The probability of disease in the exposed group as compared with that in

the unexposed group. Answer

Selected Answer:a.

RR

Correct Answer:a.

RR

• Question 1

0 out of 4 points

A phenomenon occurs when the strength of the relationship between twovariables is different according to the level of some third variableAnswer

Selected Answer:a.

synergism



Correct Answer:c.

effect modification


Cause is defined as anything producing an effect or a resultAnswer

Selected Answer:a.

True

Correct Answer:a.

True


High fat diet is a __________ factor for having certain kind of cancer.

Answer

Selected Answer: b.

Sufficient

Correct Answer:a.

Contributing


For high RR estimates (say ≥5.0) small numbers may be sufficient to setconfidence limits that exclude 1.0.Answer


Correct Answer:True


The further one departs from randomized trials, the more the research design

protects against possible biases.Answer

Selected Answer: b.

false

Correct Answer: b.

false


Example of causation in the absence of a dose-response effect



Answer

Selected Answer:e.

BMI and MI

Correct Answer:d.

Allergy to beestings


The risk of developing diarrhea among those who were exposed to an eggsalad contaminated with Salmonella compared with the risk among those who

were not exposed. Answer

Selected Answer:c.

OR

Correct Answer: d.

RR


Unrecognized bias could account for small relative risks but is unlikely to

result in large ones.Answer


Correct Answer:

a.true


Which of the following does not belong to Koch postulates

Answer

Selected

Answer:a.

the organism does not occur in other diseases as a

nonpathogenic agent.

Correct

Answer: d.the organism does not mutate, reproduce outside the culture

media.


Radiation exposure is a __________ exposure for causing leukemia. Answer



Selected Answer:c.

Sufficient

Correct Answer:c.

Sufficient


Antagonism occurs when the joint effect is less than the sum of the effects of

individual causes.Answer

Selected Answer:a.

true

Correct Answer:a.

true


Coronary artery disease has multiple causes, includingAnswer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above


When more than one cause acts together, the resulting risk may be greater or

less than would be expected by simply combining the effects of the separatecauses. This phenomenon is known asAnswer

Selected Answer: b.

biologic plausibility

Correct Answer:d.

interaction• Question 14

4 out of 4 points

The probability of disease in the exposed group as compared with that in

the unexposed group. Answer

Selected Answer:d.



RR

Correct Answer:d.

RR


Reversible associations are strong, but not perfect, evidence of a causalrelationship.Answer

Selected Answer:a.

true

Correct Answer:a.

true


Loss to follow-up is a type of selection bias in a

Answer

Selected Answer:d.

prevalence study

Correct Answer:a.

cohort study

• Question 17

0 out of 4 points

Is there a 1-to-1 relationship between “cause” and “effect?” Which causality

criterion is referred to in this question?

Answer

Selected Answer:a.

Strength

Correct Answer:e.

Specificity

• Question 18

0 out of 4 points

The evidence that oral contraceptives cause VTE and myocardial infarction (insmokers), for example, might be invoked as evidence to support the claim that

they also cause strokes. This criteria of causality is called

Answer

Selected Answer:a.

Biological plausibility



Correct Answer: b.

Analogy


The confidence interval provides information on the precision of the pointestimate (RR, IDR, or OR) and the magnitude of the association.Answer


Correct Answer:True


Research designs are ordered in terms of strength (strongest to weakest) asfollows:Answer

Selected Answer: b.

Randomized trial, case-control, cohort, cross-sectional

Correct Answer:a.

Randomized trial, cohort, case-control, cross-sectional


AIDS cannot occur without exposure to HIVAnswer

Selected Answer: a.

true

Correct Answer:a.

true


High fat diet is a __________ factor for having heart disease. Answer

Selected Answer:c.

Necessary

Correct Answer:d.

Contributing


Did the “outcome” occur after the “cause” was introduced? Which causality



criterion is referred to in this question?

Answer

Selected Answer: b.

Specificity

Correct Answer:a.

Temporality


The presence or absence of a dose-response effect may not necessarily be

evidence of causality. Answer


Correct Answer:True


High fat diet is a __________ factor for having diabetes. Answer

Selected Answer: b.

Necessary

Correct Answer:a.

Contributing


An apparent association that does not exist in nature could be merely due toAnswer

Selected Answer:c.

measurement bias

Correct Answer:d.

all of the above


Lack of temporal sequence is powerful evidence against causeAnswer

Selected Answer:a.

true



Correct Answer:a.

true


The best evidence for a cause-and-effect relationship come from randomizedcontrolled trials withAnswer

Selected Answer:e.

all of the above

Correct Answer:e.

all of the above


The main bias afflicting ecological studies isAnswer

Selected Answer:d.

non-random bias

Correct Answer:c.

ecological fallacy


In the formula, "If x happens, then y always happens," x is a __________

condition for y. Answer

Selected Answer:a.

Necessary

Correct Answer: b.

Necessary

Question)1))

4)out)of)4)points)

) )

)

Cause)is)defined)as)anything)producing)an)effect)or)a)result)Answer)) )))


True)

Correct)Answer:) )a.)))True)

)

)) )

Question)2))



4)out)of)4)points)

) )

)

Lack)of)biologic)plausibility)is)a)strong)evidence)against)causal)association.)

Answer)) )))


false)Correct)Answer:) )b.)))

false))

)) )

Question)3))

4)out)of)4)points)

) )

)

The)probability)of)disease)in)the)exposed)group)as)compared)with)that)in)the)) unexposed)group.))

Answer)))) )


RR)


RR))

)) )

Question)4))

4)out)of)4)points)

) )

)

A)drawback)to)p)values)is)that)they)do)not)provide)direct)insight)into)the)magnitude)of)the)association)or)into)the)extent)that)a)RR)point)estimate)may)

vary)by)chance)if)the)same)study)were)to)be)repeated.))

Answer))

)) )


Correct)Answer:)) )True))

)) )

Question)5))4)out)of)4)points)

) )

)

Do)the)studies)concerning)health)and)hygiene)show)a)persistent)association)

with)different)study)designs,)populations,)at)different)times,)or)geographic)

areas)and)according)to)various)study)investigators?))Which)causality)

criterion)is)appropriate)for)this)question?)Answer))

)) )


Consistency)Correct)Answer:) )d.)))

Consistency))

)) )


) )

)

An)estimate)that)measures)the)rate)with)which)new)cases)of)disease)occur)in)

the)exposed)relative)to)the)unexposed.) )))



Answer))


IDR)


IDR))

)) )

Question)7))

4)out)of)4)points)

) )

)

Biologic)gradient)refers)to)

Answer)) )))


DosePresponse)relation)


DosePresponse)relation))

)) )


) )

)

In)a)casePcontrol)study,)patients)with)brain)cancer)and)matched)controls)

without)brain)cancer)were)asked)about)cellPphone)use.)The)estimated)

relative)risk)for)at)least)100)hours)of)use)compared)to)no)or)rare)use)was)1.0)

for)all)types)of)brain)tumors)combined)(95%)confidence)interval,)0.6)to)1.5.)

This)finding)is)consistent)with:)

Answer))

)) )

Selected)

Answer:)

)c.)))

Use)of)cell)phones)is)not)associated)with)protection)of)

development)of)brain)tumors)

Correct)

Answer:)

)e.)))

All)of)the)above))

)) )


) )

)

High)fat)diet)is)a)__________)factor)for)having)certain)kind)of)cancer.)

Answer)) )))


Contributing)


Contributing))

)) )


) )

)

A)factor)which)is)indispensible)and)must)have)occurred)if)a)specifiable)state)

of)affairs)has)occurred)is)a)__________)condition.) )))



Answer))


Necessary)


Necessary))

)) )

Question)11))

0)out)of)4)points)

) )

)

Which)of)the)following)would)strengthen)your)sense)that)cell)phones)are)or)

are)not)related)to)brain)tumors?)

Answer)))) )


None)of)the)above)


All)of)the)above))

)) )

Question)12))

4)out)of)4)points)

) )

)

High)fat)diet)is)a)__________)factor)for)having)hypertension.)

Answer)) )))


Contributing)


Contributing))

)) )


) )

)

For)high)RR)estimates)(say)≥5.0)small)numbers)may)be)sufficient)to)set)confidence)limits)that)exclude)1.0.)))

Answer)))) )



)) )

Question)14))

4)out)of)4)points)

) )

)

Is)there)a)1PtoP1)relationship)between)“cause”)and)“effect?”)Which)causality)criterion)is)referred)to)in)this)question?)

Answer)))) )


Specificity)


Specificity))

)) )



Question)15))

4)out)of)4)points)

) )

)

In)both)followPup)and)casePcontrol)studies)the)single)most)important)

determinant)of)power)is))

Answer)))) )


number)of)exposed)cases))


number)of)exposed)cases)))

)) )

Question)16))

4)out)of)4)points)

) )

)

Example)of)causation)in)the)absence)of)a)dosePresponse)effect)Answer)) )))

Selected)Answer:) )d.)))Allergy)to)beestings)


Allergy)to)beestings))

)) )

Question)17))

4)out)of)4)points)

) )

)

All)the)followings)are)true)except:)

Answer)) )))

Selected)

Answer:)

)e.)))

Strong)association)is)a)clear)evidence)for)a)causal)

relationship))



relationship)))

)) )


) )

)

Unrecognized)bias)could)account)for)small)relative)risks)but)is)unlikely)to)

result)in)large)ones.)

Answer)))) )


true)


true))

)) )

Question)19))

4)out)of)4)points)

) )



)

Many)studies)conducted)in)various)geographic)regions)and)with)differing)

study)methods)report)a)reduced)rate)of)infection)associated)with)implementation)of)hygiene)intervention)programs.)Which)causality)criterion)

is)satisfied)here?)

Answer))

)) )


Consistency)


Consistency))

)) )


) )

)

The)evidence)that)oral)contraceptives)cause)VTE)and)myocardial)infarction)

(in)smokers,)for)example,)might)be)invoked)as)evidence)to)support)the)claim)

that)they)also)cause)strokes.)This)criteria)of)causality)is)called)

Answer))

)) )


Analogy))


Analogy)))

)) )

Question)21))

4)out)of)4)points)

) )

)

High)fat)diet)is)a)__________)factor)for)having)diabetes.)

Answer)) )))

Selected)Answer:) )a.)))Contributing)


Contributing))

)) )

Question)22))

0)out)of)4)points)

) )

)

By)assessing)effect)modification,)the)investigator)is)able)to)consider)how)risk)factors)work)together)to)cause)disease.)))

Answer)))) )

Selected)Answer:)) )True)Correct)Answer:)) )False)

)

)) )

Question)23))

0)out)of)4)points)

) )

)

Randomized)controlled)trials)are)well)suited)to)study)risk)factors)of)disease)

Answer)) )))



Selected)Answer:) )a.)))true)


false))

)) )


) )

)

An)alternative)to)estimation)of)the)relative)risk)(RR)and)its)confidence)

interval)(CI)is)to)estimate)

Answer)))) )


Statistical)significance)


Statistical)significance))

)) )


) )

)

Analogy)is)weak)evidence)for)cause)

Answer)) )))


true)


true))

)) )

Question)26))

0)out)of)4)points)) )

)

Antagonism)occurs)when)the)joint)effect)is)less)than)the)sum)of)the)effects)of)

individual)causes.)

Answer)))) )


false)


true))

)) )

Question)27))


)

Knowledge)of)strong)risk)factors)is)insufficient)for)effective)treatment)and)

prevention)of)the)disease)unless)the)pathogenetic)mechanism)is)clear.)

Answer)))) )


false) )))



Correct)Answer:) )b.)))false)

)


) )

)

The)main)bias)afflicting)ecological)studies)is))Answer)) )))

Selected)Answer:) )c.)))ecological)fallacy)


ecological)fallacy))

)) )

Question)29))

4)out)of)4)points)

) )

)

The)absence)of)specificity)is)weak)evidence)against)a)causePandPeffect)

relationship.)Answer))

)) )


true)


true))

)) )

Question)30))

4)out)of)4)points)

) )

)

Radiation)exposure)is)a)__________)exposure)for)causing)leukemia.)

Answer)) )))Selected)Answer:) )a.)))

Sufficient)


Sufficient))

)) )

)

4)out)of)4)points)

) )

)

A)study)where)the)effect)is)measured)at)various)points)in)time)before)and)

after)the)purported)cause)has)been)introduced)is)called)

Answer))

)) )

Selected)Answer:) )b.)))timePseries)study)


timePseries)study))

)) )

Question)2))

4)out)of)4)points)

) )



)

High)fat)diet)is)a)__________)factor)for)having)hypertension.)

Answer)) )))

Selected)Answer:) )c.)))Contributing)

Correct)Answer:) )c.)))Contributing)

)

)) )


) )

)

A)drawback)to)p)values)is)that)they)do)not)provide)direct)insight)into)the)

magnitude)of)the)association)or)into)the)extent)that)a)RR)point)estimate)may)


Answer))

)) )



)) )

Question)4))

4)out)of)4)points)

) )

)



Answer)))) )


number)of)exposed)cases))


number)of)exposed)cases)))

)) )

Question)5))

4)out)of)4)points)

) )

)

The)confidence)interval))provides)information)on)the)precision)of)the)point)estimate)(RR,)IDR,)or)OR)and)the)magnitude)of)the)association.)))

Answer)))) )



)) )

Question)6))

4)out)of)4)points)

) )

)

When)more)than)one)cause)acts)together),)the)resulting)risk)should)always)be)greater)than)would)be)expected)by)simply)combining)the)effects)of)the)

separate)causes.)))

Answer))

)) )

Selected)Answer:)) )False)

Correct)Answer:)) )False))

)) )

Question)7))



4)out)of)4)points)

) )

)

Which)came)first?)Which)causality)criterion)is)referred)to)in)this)question?)

Answer)) )))


Temporality)Correct)Answer:) )a.)))

Temporality))

)) )

Question)8))

4)out)of)4)points)

) )

)

Is)there)a)1PtoP1)relationship)between)“cause”)and)“effect?”)Which)causality)criterion)is)referred)to)in)this)question?)

Answer)))) )


Specificity)


Specificity))

)) )

Question)9))

4)out)of)4)points)

) )

)

A)factor)which)is)indispensible)and)must)have)occurred)if)a)specifiable)state)of)affairs)has)occurred)is)a)__________)condition.)

Answer)))) )

Selected)Answer:) )a.)))Necessary)


Necessary))

)) )

Question)10))

4)out)of)4)points)

) )

)

A)confidence)limits)that)includes)1.0)is)taken)to)suggest)that)it)is)unlikely)that)

the)observed)association)is)due)to)chance.)

Answer)))) )



)) )

Question)11))

4)out)of)4)points)

) )

)

Do)the)studies)concerning)health)and)hygiene)show)a)persistent)association)

with)different)study)designs,)populations,)at)different)times,)or)geographic)areas)and)according)to)various)study)investigators?))Which)causality)

criterion)is)appropriate)for)this)question?)

Answer))

)) )



Selected)Answer:) )b.)))Consistency)


Consistency))

)) )


) )

)

When)more)than)one)cause)acts)together,)the)resulting)risk)may)be)greater)

or)less)than)would)be)expected)by)simply)combining)the)effects)of)the)

separate)causes.)This)phenomenon)is)known)as)

Answer))

)) )


biologic)plausibility)


interaction))

)) )

Question)13))

4)out)of)4)points)

) )

)

Ecologic)correlation)))

Answer)))) )

Selected)Answer:)

))))An)association)between)two)variables,)the)exposure)and)the)

outcome,)and)are)measured)at)the)group)level.)))

)

Correct)

Answer:)

))))

An)association)between)two)variables,)the)exposure)and)the)

outcome,)and)are)measured)at)the)group)level.))))

)

)) )

Question)14))

4)out)of)4)points)

) )

)

Which)of)the)following)would)strengthen)your)sense)that)cell)phones)are)or)

are)not)related)to)brain)tumors?)

Answer)))) )

Selected)Answer:) )d.)))All)of)the)above)


All)of)the)above))

)) )

Question)15))

4)out)of)4)points)

) )

)

What)is)most)important)reason)for)not)conducting)a)randomized)controlled))) )



trial)(RCT)to)determine)whether)or)not)cell)phones)cause)brain)cancer?)

Answer))

Selected)Answer:) )e.)))It)would)be)unethical)

Correct)Answer:) )e.)))It)would)be)unethical)

)

)) )


) )

)

Which)of)the)following)factors)is)necassary)to)have)coronary)artery)disease?)

Answer)) )))


none)of)the)above)


none)of)the)above))

)) )

Question)17))

4)out)of)4)points)

) )

)

High)fat)diet)is)a)__________)factor)for)having)heart)disease.)

Answer)) )))


Contributing)


Contributing))

)) )


) )

)

In)the)formula,)"If)x)happens,)then)y)always)happens,")x)is)a)__________)condition)for)y.)

Answer)))) )


Necessary)


Necessary))

)) )


) )

)

The)presence)or)absence)of)a)dosePresponse)effect)may)not)necessarily)be)evidence)of)causality.))

Answer)))) )



)) )



Question)20))

4)out)of)4)points)

) )

)

Exposure)to)HIV)commonly)results)in)AIDS)after)needlesticks)

Answer)) )))

Selected)Answer:) )b.)))false)


false))

)) )

Question)21))

4)out)of)4)points)

) )

)


Answer)) )))

Selected)

Answer:)

)e.)))

Strong)association)is)a)clear)evidence)for)a)causal)relationship))



relationship)))

)) )


) )

)

Antagonism)occurs)when)the)joint)effect)is)less)than)the)sum)of)the)effects)of)

individual)causes.)

Answer)))) )



true))

)) )


) )

)

The)greater)the)magnitude)of)the)RR)the)larger)is)the)number)of)exposures)

and)outcomes)needed)to)document)it.)

Answer)))) )



)) )

Question)24))

4)out)of)4)points)

) )

)

High)fat)diet)is)a)__________)factor)for)having)diabetes.)

Answer)) )))



Selected)Answer:) )c.)))Contributing)


Contributing))

)) )


) )

)

Reversible)associations)are)strong,)but)not)perfect,)evidence)of)a)causal)

relationship.)

Answer)))) )


true)


true))

)) )


) )

)

Analogy)is)weak)evidence)for)cause)

Answer)) )))


true)


true))

)) )

Question)27))


)

An)apparent)association)that)does)not)exist)in)nature)could)be)merely)due)to)

Answer)) )))


all)of)the)above)


all)of)the)above))

)) )

Question)28))

4)out)of)4)points)

) )

)

Knowledge)of)strong)risk)factors)is)insufficient)for)effective)treatment)and)prevention)of)the)disease)unless)the)pathogenetic)mechanism)is)clear.)

Answer)))) )

Selected)Answer:) )b.)))false)

Correct)Answer:) )b.))))) )



false))

Question)29))

4)out)of)4)points)

) )

)

The)absence)of)specificity)is)weak)evidence)against)a)causePandPeffect)

relationship.)Answer))

)) )



true))

)) )

Question)30))

4)out)of)4)points)

) )

)

For)high)RR)estimates)(say)≥5.0)small)numbers)may)be)sufficient)to)set)

confidence)limits)that)exclude)1.0.)))Answer))

)) )

Selected)Answer:)) )True)) )) )4)out)of)4)points)

) )

)

For)high)RR)estimates)(say)≥5.0)small)numbers)may)be)sufficient)to)set)

confidence)limits)that)exclude)1.0.)))

Answer)))) )



)) )


) )

)

The)drawbacks)of)the)ecologic)study))

Answer)) )))

Selected)

Answer:)

)e.)))

)are)only)used)in)environmental)epidemiologic)research.)))


The)ecologic)fallacy)and)imprecise)measurement)of)

exposure.))

))

)) )


) )

)

Which)of)the)following)factors)is)necassary)to)have)coronary)artery)disease?)

Answer)) )))


none)of)the)above) )))



Correct)Answer:) )e.)))none)of)the)above)

)


) )

)

Coronary)artery)disease)has)multiple)causes,)including)Answer)) )))

Selected)Answer:) )d.)))all)of)the)above)


all)of)the)above))

)) )

Question)5))

4)out)of)4)points)

) )

)

The)lack)of)scientific)plausibility)should)deter)us)from)inferring)causality.)))

Answer)) )))Selected)Answer:)) )False)


)) )

Question)6))

4)out)of)4)points)

) )

)

Exposure)to)the)virus)is)a)__________)condition)for)contracting)chicken)pox.)Answer)) )))


Necessary)

Correct)Answer:) )b.)))Necessary)

)

)) )


) )

)

An)apparent)association)that)does)not)exist)in)nature)could)be)merely)due)to)

Answer)) )))


all)of)the)above)


all)of)the)above))

)) )


) )

)

The)suspected)cause)and)the)effect)must)be)associated)if)they)are)to)be)

considered)as)causally)related.))

Answer)))) )





true))

)) )


) )

)


Answer)) )))

Selected)

Answer:)

)e.)))


relationship))



relationship)))

)) )

Question)10))

4)out)of)4)points)

) )

)

Unrecognized)bias)could)account)for)small)relative)risks)but)is)unlikely)to)result)in)large)ones.)

Answer)))) )



true))

)) )

Question)11))

4)out)of)4)points)

) )

)

The)main)bias)afflicting)ecological)studies)is))

Answer)) )))


ecological)fallacy)


ecological)fallacy))

)) )


) )

)

A)drawback)to)p)values)is)that)they)do)not)provide)direct)insight)into)the)

magnitude)of)the)association)or)into)the)extent)that)a)RR)point)estimate)may)


Answer))

)) )

Selected)Answer:)) )True))) )





) )

)

Many)studies)conducted)in)various)geographic)regions)and)with)differing)

study)methods)report)a)reduced)rate)of)infection)associated)with)implementation)of)hygiene)intervention)programs.)Which)causality)criterion)

is)satisfied)here?)

Answer))

)) )


Consistency)

Correct)Answer:) )c.)))Consistency)

)

)) )


) )

)

The)evidence)that)oral)contraceptives)cause)VTE)and)myocardial)infarction)

(in)smokers,)for)example,)might)be)invoked)as)evidence)to)support)the)claim)

that)they)also)cause)strokes.)This)criteria)of)causality)is)called)

Answer))

)) )


Analogy))


Analogy)))

)) )

Question)15))


)

The)best)evidence)for)a)causePandPeffect)relationship)come)from)randomized)

controlled)trials)with)Answer))

)) )


all)of)the)above)


all)of)the)above))

)) )

Question)16))


)

High)fat)diet)is)a)__________)factor)for)having)heart)disease.)

Answer)) )))


Contributing)

Correct)Answer:) )b.))))) )



Contributing))

Question)17))

4)out)of)4)points)

) )

)

A)factor)which)is)indispensible)and)must)have)occurred)if)a)specifiable)state)

of)affairs)has)occurred)is)a)__________)condition.)Answer))

)) )

Selected)Answer:) )a.)))Necessary)


Necessary))

)) )

Question)18))

4)out)of)4)points)

) )

)

Loss)to)followPup)is)a)type)of)selection)bias)in)a))

Answer)) )))Selected)Answer:) )c.)))

cohort)study)


cohort)study))

)) )

Question)19))

4)out)of)4)points)

) )

)

Which)came)first?)Which)causality)criterion)is)referred)to)in)this)question?)

Answer)) )))

Selected)Answer:) )a.)))Temporality)


Temporality))

)) )

Question)20))

4)out)of)4)points)

) )

)

An)appropriate)temporal)sequence)alone)is)a)strong)evidence)for)cause)Answer)) )))


false)

Correct)Answer:) )b.)))false)

)

)) )

Question)21))

4)out)of)4)points)

) )

)

The)absence)of)specificity)is)weak)evidence)against)a)causePandPeffect))) )



relationship.)

Answer))


Correct)Answer:) )a.)))true)

)

)) )


) )

)

Does)1)cause)have)a)single)effect?))Which)causality)criterion)is)referred)to)in)

this)question?)

Answer)))) )

Selected)Answer:) )b.)))Specificity)

Correct)Answer:) )b.)))Specificity)

)

)) )


) )

)

Ideally,)no)association)should)be)accepted)as)causal)until)it)has)been)

repeatedly)and)independently)confirmed.)))

Answer)))) )



)) )


) )

)

A)study)where)the)effect)is)measured)at)various)points)in)time)before)and)

after)the)purported)cause)has)been)introduced)is)called)Answer))

)) )


timePseries)study)

Correct)Answer:) )b.)))timePseries)study)

)

)) )


) )

)



Answer)))) )


number)of)exposed)cases)) )))



Correct)Answer:) )d.)))number)of)exposed)cases))

)


) )

)

When)more)than)one)cause)acts)together,)the)resulting)risk)may)be)greater)or)less)than)would)be)expected)by)simply)combining)the)effects)of)the)

separate)causes.)This)phenomenon)is)known)as)

Answer))

)) )


interaction)


interaction))

)) )

Question)27))

4)out)of)4)points)

) )

)

Confounding)can)either)suppress)or)inflate)an)association.))

Answer)) )))



)) )

Question)28))

4)out)of)4)points)

) )

)

Do)the)studies)concerning)health)and)hygiene)show)a)persistent)association)with)different)study)designs,)populations,)at)different)times,)or)geographic)

areas)and)according)to)various)study)investigators?))Which)causality)

criterion)is)appropriate)for)this)question?)Answer))

)) )


Consistency)


Consistency))

)) )

Question)29))

4)out)of)4)points)

) )

)

Research)designs)are)ordered)in)terms)of)strength)(strongest)to)weakest)as)

follows:))Answer))

)) )


Randomized)trial,)cohort,)casePcontrol,)crossPsectional)


Randomized)trial,)cohort,)casePcontrol,)crossPsectional))

)) )



Question)30))

4)out)of)4)points)

) )

)

Weakest)of)all)research)designs)are)case)series)

Answer)) )))



true))

)) )

Sunday,)April)14,)2013)11:04:26)AM)EDT)

)

)



nstructions


Censored subjects usually terminate the interval in K-M curve.Answer

Selected Answer: False



A bias occurs when groups being compared are not equally susceptible to the

outcome of interest for reasons other than the factor under study is calledAnswer

Selected Answer:a.

measurement bias

Correct Answer: b.

assembly bias


With this strategy, data are analyzed and results presented according tosubgroups of patients of similar characteristics. Answer

Selected Answer: b.

Stratification

Correct Answer: b.

Stratification


In K-M analysis, only event occurrences define known survival time intervals.Answer


Correct Answer:True


Matching controls bias only for those variables involved in the match.Answer


Correct Answer:True

• Question 6



4 out of 4 points

Percent of patients showing some evidence of improvement following anintervention.Answer

Selected Answer:e.

Response

Correct Answer:e.

Response


Patients who are enrolled in a study can be confined to only those possessing anarrow range of characteristics, a strategy calledAnswer

Selected Answer:

b.restriction

Correct Answer: b.

restriction


factors are not necessarily the same as the prognostic factors. Answer




The best way to balance all extraneous variables between groups isAnswer

Selected Answer:c.

matching

Correct Answer:a.

randomization


External validity of a cohort study is limited withAnswer

Selected Answer:a.

randomization



Correct Answer:d.

restriction


Percent of patients who have return of disease after a disease-free interval. Answer

Selected Answer: b.

Recurrence

Correct Answer: b.

Recurrence


Prognosis studies are studies that tackle clinical questions about prognosis

in ways similar to cross-sectional studies of risk. Answer




All the following are true regarding risk and prognosis except:Answer

Selected Answer: a.

Studies of risk factors usually deal with healthy people

Correct Answer:e.

Risk factors are usually for high-probability events


A form of selection bias occurs when groups of patients assembled for study

differ in ways other than the variables under study is calledAnswer

Selected Answer:d.

information bias

Correct Answer:e.

none of the above




Community A and community B each have crude mortality rates for

coronary heart disease (CHD) of 4 per 1,000. The age-adjusted CHDmortality rate is 5 per 1,000 for community A and 3 per 1,000 for

community B. One may conclude that Answer

SelectedAnswer:

b.

Diagnosis is less accurate in community A than in

community B.

Correct

Answer:a.

Community A has a younger population than community

B.


With this strategy, for each patient in one group, one or more patients with the

same characteristics (except for the factor of interest) are selected for acomparison group. Answer

Selected Answer:e.

Matching

Correct Answer:e.

Matching


In the investigation of an epidemic of a fatal disease such as SARS, the mostappropriate measure to describe the frequency of death from the disease is the:Answer

Selected Answer: b.

Case-fatality rate

Correct Answer: b.

Case-fatality rate


All the following statements are true except:Answer

Selected

Answer:a.

Randomization is the only feasible way of dealing with many



variables at one time

Correct

Answer:a.


variables at one time


For each patient in one group one or more patients with the samecharacterisitics (except for the factor of interest) is selected for a comparison

group. This approach is calledAnswer

Selected Answer:e.

matching

Correct Answer:e.

matching


A bias occurs when patients selected for study are systematically differentfrom those the results are generalized to is calledAnswer

Selected Answer: b.

Sampling bias

Correct Answer: b.

Sampling bias


Number of people dying of a specific disease. Answer

Selected Answer:a.

Case fatality

Correct Answer: b.

Disease specific mortality


In most clinical situations, the joint effects of two or more variables might be

greater than the sum of their individual effects.Answer




Correct Answer:True


Applying results from referral centers to community practice would result in

falsely underestimating the likelihood of recurrent seizures.Answer




Calendar time refers to the way we usually think of time and the way clinical

trials are designed.Answer


Correct Answer:True


Percent of patients entering a phase in which disease is no longer detectable. Answer

Selected Answer:e.

Remission

Correct Answer:e.

Remission


The standardized death rate (adjusted for preoperative risk) in hospital A is the

same as the standardized rate for hospital B. The crude rate for hospital A ishigher than the crude rate for hospital B. This indicates that more high-risk

patients are treated at hospital B.Answer




Two rates can be compared without bias related to extraneous factor if they areadjusted to equalize the weight given to the factor. This process is calledAnswer

Selected Answer: b.



standardization

Correct Answer: b.

standardization


Randomization not only balances variables known to affect prognosis, but italso balances those that are unknown.Answer


Correct Answer:True


In preparing K-M survival analysis, each subject is characterized by three

variables. Answer

Selected Answer: b.

serial time

Correct Answer:d.

time of entry


Using the results of population-based studies for children seen in referral

centers would overestimate rates for those children. Answer




The standardized death rate (adjusted for preoperative risk) in hospital A is the

same as the standardized rate for hospital B. The crude rate for hospital A is

higher than the crude rate for hospital B. This indicates that more high-risk patients are treated at hospital B.Answer




The effects of possible prognostic factors, relative to one another, can be



summarized usingAnswer

Selected Answer:d.

hazard ratio

Correct Answer: d.

hazard ratio


All the following ways of dealing with extraneous differences between groups

do not deal with risk or prognostic factors that are not known at the time of thestudy except: Answer

Selected Answer:a.

Stratification

Correct Answer:c.

Randomization


Percent of patients who have the disease back after a disease free interval Answer

Selected Answer:c.

Recurrence

Correct Answer:c.

Recurrence


Applying results from referral centers to community practice would result infalsely underestimating the likelihood of recurrent seizures.Answer




A way of combining data on all the variables, based on certain assumptionsabout their distributions and relationships is calledAnswer

Selected Answer:e.



Mathematical modeling

Correct Answer:e.

Mathematical modeling



Selected

Answer:d.

In cohort studies, it is usually not possible to randomize risk or prognostic factors

Correct

Answer:e.

Matching by age and sex should be avoided because these

variables are strongly related to risk or prognosis for many

diseases


The term inception cohort is used to describe a group of people that isassembled at theAnswer

Selected Answer:a.

onset, or inception, of their disease

Correct Answer:a.

onset, or inception, of their disease


The prognosis of disease without medical intervention is calledAnswer

Selected Answer:d.

all of the above

Correct Answer: b.

natural history of the disease


A clinical course duration variable for each subject, having a beginning and anend anywhere along the time line of the complete study. Answer

Selected Answer:a.



Time-to-event

Correct Answer:a.

Time-to-event


Matching controls bias only for those variables involved in the match.Answer


Correct Answer:True


Two rates can be compared without bias related to extraneous factor if they are

adjusted to equalize the weight given to the factor. This process is called

Answer

Selected Answer: b.

standardization

Correct Answer: b.

standardization


All ways of dealing with extraneous differences between groups are limited to

variables that are singled out for consideration except:

Answer

Selected Answer:c.

Randomization

Correct Answer:c.

Randomization


Prediction of the future course of disease following its onset is calledAnswer

Selected Answer:d.

prognosis

Correct Answer:d.

prognosis




Measurement bias is possible whenAnswer

Selected

Answer:d.

patients in one subgroup of a cohort stand a better chance of having their outcomes detected than those in another subgroup.

Correct

Answer:d.

patients in one subgroup of a cohort stand a better chance of

having their outcomes detected than those in another subgroup.


The two main determinants of disease prognosis are incidence rate and duration of

illness. Answer




All the following are prognostic factors for myocardial infarction exceptAnswer

Selected Answer:c.

LDL/HDL

Correct Answer:c.

LDL/HDL• Question 18

4 out of 4 points

The prognosis of disease that has come under medical care and has been

treated in a variety of ways that affect the subsequent course of events is calledAnswer

Selected Answer: b.

clinical course of the disease

Correct Answer: b.

clinical course of the disease• Question 19

0 out of 4 points

Multivariable analysis is the only feasible way of dealing with many variablesat one time.Answer




Correct Answer:True


A phase in which disease is no longer detectable

Answer

Selected Answer:d.

Remission

Correct Answer:d.

Remission


Randomization not only balances variables known to affect prognosis, but italso balances those that are unknown.Answer


Correct Answer:True


When important data are not available, it is possible to estimate their potentialeffects on the study usingAnswer

Selected Answer:e.

Mathematical modelingCorrect Answer:

b.

Sensitivity analysis


A new treatment is developed that prevents death but does not produce

recovery from disease. Which of the following will occur?

Answer

Selected Answer:d.

Case-fatality will increase

Correct Answer:e.

Prevalence will increase


In most clinical situations, the joint effects of two or more variables might be



greater than the sum of their individual effects.Answer


Correct Answer:True



Selected

Answer:a.

Randomization is the only feasible way of dealing with manyvariables at one time

Correct

Answer:a.


variables at one time• Question 26

4 out of 4 points

All the following are true regarding risk and prognosis except:Answer

Selected Answer:e.


Correct Answer:e.



In the investigation of an epidemic of a fatal disease such as SARS, the mostappropriate measure to describe the frequency of death from the disease is the:Answer

Selected Answer:a.

Case-fatality rate

Correct Answer:a.

Case-fatality rate


K-M survival curves that have many small steps usually have a limited number

of participating subjects, whereas curves with large steps usually have a higher number of subjects and are thus not as accurate.Answer






In 2002, a land mark study has showed hormone replacement therapy (HRT)

may increase the risk of breast cancer among post-menopausal women.Therefore, a decrease of breast cancer incidence is expected. Answer


Correct Answer:True


In 2002, a land mark study has showed hormone replacement therapy (HRT) may

increase the risk of breast cancer among post-menopausal women. How will this

impact the incidence and case-fatality rate from breast cancer in the US?

Answer

Selected Answer:a.

An increase in both

Correct Answer:f.

A decrease of beast incidence

!

Question!1!.4!out!of!4!points!

!!!

!All!the!following!statements!about!Kaplan8Meier!survival!curves!are!true!except:!

Answer!!!


Account!for!confounding!or!effect!modification!by!other!covariates!!!


Account!for!confounding!or!effect!modification!by!other!covariates!!!


!!!

!In!myocardial!infarction!

Answer!!!


Age!and!gender!are!both!risk!and!prognostic!factors!!Correct!Answer:!!e.!!!Age!and!gender!are!both!risk!and!prognostic!factors!!

!!


!A!way!of!combining!data!on!all!the!variables,!based!on!certain!assumptions!about!

their!distributions!and!relationships!is!called!!



Answer!!!

Selected!Answer:!!e.!!!Mathematical!modeling!!

Correct!Answer:!!e.!!!Mathematical!modeling!!


!Community!A!and!community!B!each!have!crude!mortality!rates!for!coronary!heart!

disease!(CHD)!of!4!per!1,000.!The!age8adjusted!CHD!mortality!rate!is!5!per!1,000!for!

community!A!and!3!per!1,000!for!community!B.!One!may!conclude!that!!

!

Answer!!!


Community!A!has!a!younger!population!than!community!B.!

!!

Correct!Answer:!!d.!!!Community!A!has!a!younger!population!than!community!B.!!!


!!!

!A!new!treatment!is!developed!that!prevents!death!but!does!not!produce!recovery!from!disease.!Which!of!the!following!will!occur?!!

!Answer!!!


Prevalence!will!increase!!!


Prevalence!will!increase!

!!

!!


!!!

!Matching!controls!bias!only!for!those!variables!involved!in!the!match.!Answer!!!




!All!the!following!are!true!regarding!risk!and!prognosis!except:!

Answer!!!


Risk!factors!are!usually!for!high8probability!events!!




Risk!factors!are!usually!for!high8probability!events!!!!

.!Question!!.4!out!of!4!points!!!!

!Multivariable!analysis!is!the!only!feasible!way!of!dealing!with!many!variables!at!one!time.!Answer!!!



!!


!!!

!External!validity!of!a!cohort!study!is!limited!with!

Answer!!!


restriction!!Correct!Answer:!!d.!!!restriction!!


!!!

!The!term!inception!cohort!is!used!to!describe!a!group!of!people!that!is!assembled!at!the!!


onset,!or!inception,!of!their!disease!!!

Correct!Answer:!!a.!!!onset,!or!inception,!of!their!disease!!!

!!


!!!

!Two!rates!can!be!compared!without!bias!related!to!extraneous!factor!if!they!are!

adjusted!to!equalize!the!weight!given!to!the!factor.!This!process!is!called!!

Answer!!!

Selected!Answer:!!b.!!!standardization!!


standardization!!!!


!Number!of!people!dying!of!a!specific!disease.!!

Answer!!!


Disease!specific!mortality!



!!

Correct!Answer:!!a.!!!Disease!specific!mortality!

!!!!

.!Question!13!.4!out!of!4!points!!!!!A!bias!occurs!when!groups!being!compared!are!not!equally!susceptible!to!the!

outcome!of!interest!for!reasons!other!than!the!factor!under!study!is!called!

Answer!!!


assembly!bias!!


assembly!bias!!

!!


!!!!The!prognosis!of!disease!that!has!come!under!medical!care!and!has!been!treated!in!a!variety!of!ways!that!affect!the!subsequent!course!of!events!is!called!


clinical!course!of!the!disease!!

Correct!Answer:!!b.!!!clinical!course!of!the!disease!!


!!!

!Matching!can!account!for!many!variables!at!a!time.!Answer!!!



!!


!!!

!All!the!following!ways!of!dealing!with!extraneous!differences!between!groups!do!

not!deal!with!risk!or!prognostic!factors!that!are!not!known!at!the!time!of!the!study!except:!

!


Randomization!!!


Randomization!

!!

!!




!!!!The!sum!of!the!number!of!years!of!observation!in!each!individual!in!the!study.!

!Answer!!!

Selected!Answer:!!a.!!!Person!years!!!


Person!years!

!!

!!


!!!

!K8M!survival!curves!that!have!many!small!steps!usually!have!a!limited!number!of!

participating!subjects,!whereas!curves!with!large!steps!usually!have!a!higher!

number!of!subjects!and!are!thus!not!as!accurate.!Answer!!!Selected!Answer:!!!False!!



!!!!In!preparing!K8M!survival!analysis,!each!subject!is!characterized!by!three!variables.!

!Answer!!!


time!of!entry!!!


time!of!entry!

!!

!!


!!!

!Cigarette!smoking!is!a!prognostic!factor!for!myocardial!infarction!Answer!!!




!All!the!following!are!prognostic!factors!for!myocardial!infarction!except!!

Answer!!!


LDL/HDL!!!




LDL/HDL!!!!!


!Percent!of!patients!entering!a!phase!in!which!disease!is!no!longer!detectable!is!known!as!Answer!!!


Response!!!


Remission!!!

!!


!!!

!Risk!factors!are!not!necessarily!the!same!as!the!prognostic!factors.!

Answer!!!Selected!Answer:!!!True!!Correct!Answer:!!!True!!


!!!

!A!form!of!migration!bias!occurs!when!patients!move!from!one!group!to!another!in!the!cohort!during!follow8up!is!called!!


crossover!bias!!

Correct!Answer:!!b.!!!crossover!bias!!

!!


!!!

!In!a!case8control!study!that!includes!prevalent!cases!of!disease!the!results!may!be!

confounded!by!factors!that!affect!survival.!

Answer!!!

Selected!Answer:!!!True!!Correct!Answer:!!!True!!

!!


!In!most!clinical!situations,!the!joint!effects!of!two!or!more!variables!might!be!greater!than!the!sum!of!their!individual!effects.!!!

Answer!!!



!!




!!!!Life!tables!or!Kaplan!Meier!plots.!


Observed!survival!!!Correct!Answer:!!c.!!!

Observed!survival!

!!

!!


!!!

!The!degree!to!which!a!measurement!truly!measures!what!it!purports!to!measure!is!!

Answer!!!


validity!!Correct!Answer:!!b.!!!validity!!


!!!

!In!a!Cox!proportional!hazard!regression,!the!exponential!!of!regression!coefficient!estimates!is!called!!

!Answer!!!


Hazard!ratio!!!!


Hazard!ratio!!

!!

!!


!!!

!Percent!of!patients!surviving!5!years!from!some!point!in!the!course!of!the!disease.!Answer!!!


Five8year!survival!!!

Correct!Answer:!!c.!!!Five8year!survival!

!!

!!

.Thursday,!March!2,!2013!7:09:25!PM!EDT!

!



OK!!

!

Question!1!.4!out!of!4!points!!!!

!Time!at!which!50%!of!patients!still!alive.!


Median!survival!time!!!


Median!survival!time!

!!

!!


!!!

!All!the!following!ways!of!dealing!with!extraneous!differences!between!groups!do!

not!deal!with!risk!or!prognostic!factors!that!are!not!known!at!the!time!of!the!study!except:!

!Answer!!!

Selected!Answer:!!e.!!!Randomization!

!!

Correct!Answer:!!e.!!!Randomization!

!!!!


!All!the!following!rates!are!commonly!used!to!describe!prognosis!except:!

Answer!!!


attributable!risk!!


attributable!risk!!

!!


!!!

!Cigarette!smoking!is!a!prognostic!factor!for!myocardial!infarction!

Answer!!!

Selected!Answer:!!!False!!



!!!



!A!bias!occurs!when!groups!being!compared!are!not!equally!susceptible!to!the!

outcome!of!interest!for!reasons!other!than!the!factor!under!study!is!called!Answer!!!

Selected!Answer:!!b.!!!assembly!bias!!

Correct!Answer:!!b.!!!assembly!bias!!!!


!!!

!In!K8M!analysis,!only!event!occurrences!define!known!survival!time!intervals.!

Answer!!!



!!


!!!!Percent!of!patients!entering!a!phase!in!which!disease!is!no!longer!detectable.!Answer!!!

Selected!Answer:!!e.!!!Remission!

!!

Correct!Answer:!!e.!!!Remission!

!!!!

.!Question!!.4!out!of!4!points!

!!!!In!most!clinical!situations,!the!joint!effects!of!two!or!more!variables!might!be!

greater!than!the!sum!of!their!individual!effects.!!!

Answer!!!



!!


!!!!Patients!who!are!enrolled!in!a!study!can!be!confined!to!only!those!possessing!a!

narrow!range!of!characteristics.!This!strategy!is!called!

!Answer!!!

Selected!Answer:!!b.!!!Restriction!!


Restriction!!

!!




!!!

!A!bias!occurs!when!patients!selected!for!study!are!systematically!different!from!those!the!results!are!generalized!to!is!called!


Sampling!bias!!Correct!Answer:!!b.!!!Sampling!bias!!

!!


!!!

!All!the!following!statements!are!true!except:!

Answer!!!


Randomization!is!the!only!feasible!way!of!dealing!with!many!variables!at!one!time!!


Randomization!is!the!only!feasible!way!of!dealing!with!many!variables!at!one!time!!!!.!Question!12!.4!out!of!4!points!

!!!!In!2002,!a!land!mark!study!has!showed!hormone!replacement!therapy!(HRT)!may!

increase!the!risk!of!breast!cancer!among!post8menopausal!women.!Therefore,!a!

decrease!of!breast!cancer!incidence!is!expected.!Answer!!!


!!


!The!term!inception!cohort!is!used!to!describe!a!group!of!people!that!is!assembled!at!

the!!

Answer!!!


onset,!or!inception,!of!their!disease!!!


onset,!or!inception,!of!their!disease!!!!!


!!!!Prediction!of!the!future!course!of!disease!following!its!onset!is!called!

Answer!!!Selected!Answer:!!d.!!!

prognosis!!


prognosis!!

!!




!!!!The!effects!of!possible!prognostic!factors,!relative!to!one!another,!can!be!

summarized!using!!Answer!!!

Selected!Answer:!!d.!!!hazard!ratio!!Correct!Answer:!!d.!!!

hazard!ratio!!

!!


!!!

!Measurement!bias!is!possible!when!

Answer!!!


patients!in!one!subgroup!of!a!cohort!stand!a!better!chance!of!having!their!outcomes!

detected!than!those!in!another!subgroup.!!Correct!Answer:!!d.!!!patients!in!one!subgroup!of!a!cohort!stand!a!better!chance!of!having!their!outcomes!

detected!than!those!in!another!subgroup.!!!!


!!!!All!the!following!are!examples!of!when!times8to8events!may!be!important!end8point!

variables!except:!!

Answer!!!

Selected!Answer:!!c.!!!cancer!survival!times!

!!


time!to!complete!a!bypass!graft!

!!

!!


!!!!If!the!age8standardized!mortality!rate!in!a!population!is!lower!than!the!crude!rate!

this!means!that!the!population!has!a!higher!proportion!of!older!people!than!the!

standard!population.!!Answer!!!


!!


!!!



!Two!rates!can!be!compared!without!bias!related!to!extraneous!factor!if!they!are!

adjusted!to!equalize!the!weight!given!to!the!factor.!This!process!is!called!!Answer!!!

Selected!Answer:!!b.!!!standardization!!

Correct!Answer:!!b.!!!standardization!!!!


!!!

!Percent!of!patients!showing!some!evidence!of!improvement!following!an!

intervention.!!

Answer!!!


Response!

!!

Correct!Answer:!!d.!!!Response!!!


!!!

!Censored!subjects!usually!terminate!the!interval!in!K8M!curve.!Answer!!!


!!


!Data!are!analyzed!and!results!presented!according!to!subgroups!of!patients!of!

similar!characteristics.!This!approach!is!called!!

Answer!!!


stratification!!


stratification!!!!


!!!!K8M!survival!curves!that!have!many!small!steps!usually!have!a!limited!number!of!

participating!subjects,!whereas!curves!with!large!steps!usually!have!a!higher!number!of!subjects!and!are!thus!not!as!accurate.!

Answer!!!



!!




!!!!A!clinical!course!duration!variable!for!each!subject,!having!a!beginning!and!an!end!

anywhere!along!the!time!line!of!the!complete!study.!!

Answer!!!Selected!Answer:!!a.!!!Time8to8event!

!!


Time8to8event!

!!

!!


!!!

!In!a!well8designed!clinical!trial!of!treatment!of!ovarian!cancer,!remission!rate!at!one!

year!is!similar!for!a!new!drug!and!usual!care,!The!p8value!is!0.4.!What!is!the!interpretation!of!this!information?!!Answer!!!

Selected!Answer:!!c.!!!it!is!not!possible!to!decide!on!whether!one!treatment!is!better!than!the!other!using!

this!information!alone.!


it!is!not!possible!to!decide!on!whether!one!treatment!is!better!than!the!other!using!this!information!alone.!

!!


!!!

!With!this!strategy,!data!are!analyzed!and!results!presented!according!to!subgroups!

of!patients!of!similar!characteristics.!

!

Answer!!!


Stratification!!!


Stratification!!!


!!!

!All!the!following!are!prognostic!factors!for!myocardial!infarction!except!!

Answer!!!




LDL/HDL!!!

Correct!Answer:!!c.!!!LDL/HDL!!!


!!!!Life!tables!or!Kaplan!Meier!plots.!Answer!!!


Observed!survival!

!!


Observed!survival!

!!

!!


!!!!The!best!way!to!balance!all!extraneous!variables!between!groups!is!!Answer!!!

Selected!Answer:!!a.!!!randomization!!


randomization!!!!


!In!a!Cox!proportional!hazard!regression,!the!exponential!!of!regression!coefficient!

estimates!is!called!!!

Answer!!!


Hazard!ratio!!

!!


Hazard!ratio!!

!!!!

.Thursday,!March!2,!2013!7:21:41!PM!EDT!

!OK!!

.!

Question!1!.4!out!of!4!points!!!!

!With!this!strategy,!data!are!analyzed!and!results!presented!according!to!subgroups!

of!patients!of!similar!characteristics.!



!


Stratification!!!

Correct!Answer:!!c.!!!Stratification!!!

!!


!!!

!Matching!can!account!for!many!variables!at!a!time.!

Answer!!!



!!

.!Question!3!.4!out!of!4!points!!!!!The!degree!to!which!a!measurement!truly!measures!what!it!purports!to!measure!is!!


validity!!

Correct!Answer:!!b.!!!validity!!


!!!

!In!survival!analysis,!censoring!occurs!only!terminally!at!the!end!of!the!study.!Answer!!!



!!


!!!

!All!the!following!are!examples!of!when!times8to8events!may!be!important!end8point!

variables!except:!!

Answer!!!

Selected!Answer:!!c.!!!time!to!complete!a!bypass!graft!


time!to!complete!a!bypass!graft!

!!

!!




!!!

!Applying!results!from!referral!centers!to!community!practice!would!result!in!falsely!underestimating!the!likelihood!of!recurrent!seizures.!

Answer!!!Selected!Answer:!!!False!!

Correct!Answer:!!!False!!!!.!Question!7!.4!out!of!4!points!

!!!

!Life!tables!or!Kaplan!Meier!plots.!

Answer!!!


Observed!survival!

!!


Observed!survival!

!!!!.!Question!!.4!out!of!4!points!

!!!!Case!fatality!rate!for!a!given!disease!refers!to!!

!


the!percentage!of!deaths!among!cases!of!the!disease!!!


the!percentage!of!deaths!among!cases!of!the!disease!!!

!!


!!!

!When!important!data!are!not!available,!it!is!possible!to!estimate!their!potential!

effects!on!the!study!using!

Answer!!!

Selected!Answer:!!b.!!!Sensitivity!analysis!!


Sensitivity!analysis!!!!


!The!prognosis!of!disease!without!medical!intervention!is!called!

Answer!!!


natural!history!of!the!disease!!




natural!history!of!the!disease!!!!


!Calendar!time!refers!to!the!way!we!usually!think!of!time!and!the!way!clinical!trials!are!designed.!!Answer!!!



!!


!!!

!The!proportion!of!cases!of!a!specified!disease!or!condition!which!are!fatal!within!a!

specified!time.!

!

Answer!!!Selected!Answer:!!c.!!!Case!fatality!rate!


Case!fatality!rate!

!!!!


!A!bias!occurs!when!groups!being!compared!are!not!equally!susceptible!to!the!

outcome!of!interest!for!reasons!other!than!the!factor!under!study!is!called!Answer!!!


assembly!bias!!


assembly!bias!!

!!


!!!!All!the!following!are!true!regarding!risk!and!prognosis!except:!

Answer!!!

Selected!Answer:!!e.!!!Risk!factors!are!usually!for!high8probability!events!!

Correct!Answer:!!e.!!!Risk!factors!are!usually!for!high8probability!events!!

!!


!!!



!The!prognosis!of!disease!that!has!come!under!medical!care!and!has!been!treated!in!

a!variety!of!ways!that!affect!the!subsequent!course!of!events!is!called!Answer!!!

Selected!Answer:!!b.!!!clinical!course!of!the!disease!!

Correct!Answer:!!b.!!!clinical!course!of!the!disease!!!!


!!!

!Percent!of!patients!who!have!return!of!disease!after!a!disease8free!interval!is!

known!as!

Answer!!!


Recurence!!


Recurence!!!!.!Question!17!.4!out!of!4!points!

!!!!Randomization!not!only!balances!variables!known!to!affect!prognosis,!but!it!also!

balances!those!that!are!unknown.!

Answer!!!Selected!Answer:!!!True!!



!!!!Multivariable!analysis!is!the!only!feasible!way!of!dealing!with!many!variables!at!one!

time.!

Answer!!!



!!


!!!!Prognosis!can!be!described!as!

Answer!!!

Selected!Answer:!!c.!!!either!a!clinical!course!or!the!natural!history!of!disease!!

Correct!Answer:!!c.!!!either!a!clinical!course!or!the!natural!history!of!disease!!

!!


!!!

!In!myocardial!infarction!



Answer!!!

Selected!Answer:!!e.!!!Age!and!gender!are!both!risk!and!prognostic!factors!!

Correct!Answer:!!e.!!!Age!and!gender!are!both!risk!and!prognostic!factors!!


!External!validity!of!a!cohort!study!is!limited!with!

Answer!!!


restriction!!


restriction!!

!!


!!!!In!a!well8designed!clinical!trial!of!treatment!of!ovarian!cancer,!remission!rate!at!one!year!is!similar!for!a!new!drug!and!usual!care,!The!p8value!is!0.4.!What!is!the!

interpretation!of!this!information?!!Answer!!!


it!is!not!possible!to!decide!on!whether!one!treatment!is!better!than!the!other!using!this!information!alone.!


it!is!not!possible!to!decide!on!whether!one!treatment!is!better!than!the!other!using!

this!information!alone.!!!

!!


!!!

!A!phase!in!which!disease!is!no!longer!detectable!

Answer!!!


Remission!!Correct!Answer:!!e.!!!

Remission!!


!!!!Percent!of!patients!entering!a!phase!in!which!disease!is!no!longer!detectable!is!

known!as!

Answer!!!


Remission!!!




Remission!!!!!


!The!standardized!death!rate!(adjusted!for!preoperative!risk)!in!hospital!A!is!the!same!as!the!standardized!rate!for!hospital!B.!!The!crude!rate!for!hospital!A!is!higher!than!the!crude!rate!for!hospital!B.!This!indicates!that!more!high8risk!patients!are!

treated!at!hospital!B.!

Answer!!!



!!


!!!

!Percent!of!patients!who!have!return!of!disease!after!a!disease8free!interval.!

Answer!!!Selected!Answer:!!b.!!!Recurrence!

!!Correct!Answer:!!b.!!!

Recurrence!

!!!!


!In!2002,!a!land!mark!study!has!showed!hormone!replacement!therapy!(HRT)!may!

increase!the!risk!of!breast!cancer!among!post8menopausal!women.!Therefore,!the!case!fatality!rate!is!likely!to!have!major!reduction.!

Answer!!!



!!


!!!

!In!a!case8control!study!that!includes!prevalent!cases!of!disease!the!results!may!be!confounded!by!factors!that!affect!survival.!

Answer!!!



!!!

!Percent!of!patients!entering!a!phase!in!which!disease!is!no!longer!detectable.!

Answer!!!




Remission!

!!Correct!Answer:!!b.!!!

Remission!!!


!Percent!of!patients!with!disease!who!die!of!it.!

Answer!!!


Case!fatality!

!!


Case!fatality!

!!


Percent of patients entering a phase in which disease is no longer detectable. Answer

Selected Answer:a.

Remission

Correct Answer:a.

Remission

• Question 2

4 out of 4 points

Calendar time refers to the way we usually think of time and the way clinical

trials are designed.Answer


Correct Answer:True


In survival analysis, censoring occurs only terminally at the end of the study. Answer




A transparent way of recognizing and controlling for bias isAnswer



Selected Answer: b.

standardization

Correct Answer:a.

stratification


A new treatment is developed that prevents death but does not produce

recovery from disease. Which of the following will occur?

Answer

Selected Answer:e.


Correct Answer:e.



A bias occurs when groups being compared are not equally susceptible to theoutcome of interest for reasons other than the factor under study is calledAnswer

Selected Answer: b.

assembly bias

Correct Answer: b.

assembly bias


The effects of possible prognostic factors, relative to one another, can besummarized usingAnswer

Selected Answer:d.

hazard ratio

Correct Answer:d.

hazard ratio• Question 8

4 out of 4 points

The sum of the number of years of observation in each individual in the study. Answer

Selected Answer:a.

Person years



Correct Answer:a.

Person years


A form of migration bias occurs when patients move from one group toanother in the cohort during follow-up is calledAnswer

Selected Answer: b.

crossover bias

Correct Answer: b.

crossover bias


K-M survival curves that have many small steps usually have a limited number of participating subjects, whereas curves with large steps usually have a higher

number of subjects and are thus not as accurate.Answer




All the following statements about Cox Proportional Hazards are true except:Answer

Selected Answer:e.

none of the above

Correct Answer:e.

none of the above


Data are analyzed and results presented according to subgroups of patients of

similar characteristics. This approach is calledAnswer

Selected Answer:c.

stratification

Correct Answer:c.

stratification




Applying results from referral centers to community practice would result infalsely underestimating the likelihood of recurrent seizures.Answer




Percent of patients who have return of disease after a disease-free interval is

known asAnswer

Selected Answer:d.

Recurence

Correct Answer:d.

Recurence


Percent of patients with disease who die of it. Answer

Selected Answer:e.

Case fatality

Correct Answer:e.

Case fatality


Prediction of the future course of disease following its onset is calledAnswer

Selected Answer:d.

prognosis

Correct Answer:d.

prognosis


External validity of a cohort study is limited withAnswer

Selected Answer:d.

restriction



Correct Answer:d.

restriction


Multivariable analysis is the only feasible way of dealing with many variablesat one time.Answer


Correct Answer:True


Percent of patients showing some evidence of improvement following anintervention.Answer

Selected Answer:d.

Response

Correct Answer:d.

Response


A bias occurs when patients selected for study are systematically differentfrom those the results are generalized to is calledAnswer

Selected Answer: b.

Sampling bias

Correct Answer: b.

Sampling bias


Measurement bias is possible whenAnswer

SelectedAnswer:

d.



Correct

Answer:d.






Two rates can be compared without bias related to extraneous factor if they areadjusted to equalize the weight given to the factor. This process is calledAnswer

Selected Answer: b.

standardization

Correct Answer: b.

standardization


The best way to balance all extraneous variables between groups isAnswer

Selected Answer:

a.randomization

Correct Answer:a.

randomization


All the following are prognostic factors for myocardial infarction exceptAnswer

Selected Answer:c.

LDL/HDLCorrect Answer:

c.

LDL/HDL


In 2002, a land mark study has showed hormone replacement therapy (HRT) may

increase the risk of breast cancer among post-menopausal women. How will this

impact the incidence and case-fatality rate from breast cancer in the US?

Answer

Selected Answer:

d.A decrease of beast incidence

Correct Answer:d.

A decrease of beast incidence


All the following ways of dealing with extraneous differences between groups



do not deal with risk or prognostic factors that are not known at the time of the

study except: Answer

Selected Answer: b.

Randomization

Correct Answer: b.

Randomization


In calculating case fatality rate, the denominator is the total population in the

study. Answer


Correct Answer:

False


When important data are not available, it is possible to estimate their potential

effects on the study usingAnswer

Selected Answer: b.

Sensitivity analysis

Correct Answer: b.

Sensitivity analysis• Question 29

4 out of 4 points


Selected

Answer:a.


Correct

Answer:a.



Matching can account for many variables at a time.Answer





!




Factorial design is suitable for testing for Interaction.Answer


Correct Answer:True


Clinical trial randomization of study subjects is performed to reduce theinfluence of Answer

Selected Answer:c.

Selection bias

Correct Answer:c.

Selection bias


Parallel designs only employ randomized control groupsAnswer

Selected Answer: b.

False

Correct Answer: b.

False• Question 4

0 out of 4 points

Pre–post designs with no control group is the most commonly encounteredquasi-experimental designs.Answer




Intention-to-treat analysis entails analyzing the results without regard tosubject compliance.Answer


Correct Answer:True




All the following are advantages of pre and post designs except Answer

Selected Answer:d.

No history bias

Correct Answer:d.

No history bias


All the following are true in a randomized control trial (RCT) except:Answer

Selected

Answer:c.

Baseline characteristics of intervention and control groups should be

similar

Correct Answer:a.

The sample size required depends on the hypothesis


An advantage of analysis by "intention to treat" is thatAnswer

Selected

Answer:d.

It describes the consequences of offering treatments whether or

not they are actually taken

Correct

Answer:d.




In clinical trials with parallel groups, random allocation guarantees that the

groups will be similar.Answer






Observational studies of treatment effects are likely to have all of thefollowing advantages over randomized controlled trials except

Answer

Selected

Answer:a.

Treatment groups would have had a similar prognosis exceptfor treatment itself

Correct

Answer:a.

Treatment groups would have had a similar prognosis except

for treatment itself


All the following are advantages of parallel designs with historical controlexcept Answer

Selected Answer:e.

Eliminate time trend differences

Correct Answer:e.



Factorial design is suitable for Answer

Selected Answer:c.

a or b

Correct Answer:c.

a or b


Randomized controlled trials are observation studies because study arms are

observed for outcomes.Answer






All the following statements about parallel design are true except:Answer

SelectedAnswer:

e.

Each subject is randomized to one and only one treatment.

Correct

Answer:d.

Good if the intra-patients variability is relatively small

compared to the inter-patients variability


All the following studies are observational except:Answer

Selected Answer: b.

case-control

Correct Answer:d.

quasi-experimental


Compared to RCT, in quasi-experimental designAnswer

Selected Answer:c.

Both A and B are true

Correct Answer:c.



A weakness of randomized controlled trials is that they are prone to misclassification of

exposure status.Answer






As heterogeneity is restricted, the internal validity of the study is improved.Answer


Correct Answer:True


Always analyze the results of the subjects according to the group they were

randomized to. This method is known asAnswer

Selected Answer: b.

blinded analysis

Correct Answer: c.

intention to treat


Incomplete follow-up in clinical trials Answer

Selected Answer:c.

Will always bias results but direction unclear

Correct Answer: b.

May be a cause of bias


Total number of phases in clinical trials Answer

Selected Answer:d.

5

Correct Answer:d.

5




In a hospital-based clinical trial of the management of paranoid schizophrenia,relief of symptoms in patients treated with a new drug is compared with

symptom relief among patients previously treated with a standard drug. Whichof the following may bias the analysis of the relative benefits of the new and

standard drugs? Answer

Selected

Answer: b.

Changes over time in the methods used to assess symptom

relief

Correct Answer:d.

All of the above


Quasi experimental study design can also be used in situations where there are practical or ethical barriers to conducting a true RCT.Answer


Correct Answer:True


A clinical trial phase where investigators initially evaluate how well the

treatment works Answer

Selected Answer:a.

Phase II

Correct Answer:a.

Phase II


Parallel designs are good if the intra-subjects variability relatively small

compared to the inter-subjects variability.Answer






When participants are repeatedly observed using the same ‘test’, there is a possibility of learning effect and this could lead to

Answer

Selected Answer: b.

Testing bias

Correct Answer: b.

Testing bias


In a randomized controlled trial, a beta-blocker drug is found to be moreeffective than placebo for stage fright. Participants taking the beta-blocker

tended to have a lower pulse rate and to feel more lethargic, which are knowneffects of this drug. In this situation, blinding is possible for which of the

following:Answer

Selected Answer:d.

A and B

Correct Answer:c.

The investigators who assess outcome


Researchers want to assess if there is an association between cigarette smoking and strokes. Of

the following, which is the best study design to assess for this association?Answer

Selected Answer: b.

Prospective cohort study

Correct Answer: b.



There is generally an increased threat to the internal and external validity of quasi-experimental study compared to a randomized controlled trial.Answer


Correct Answer:True




What is the key difference between an observational study and an experiment? Answer

SelectedAnswer:

d.

In observational studies, subjects do not receive any

intervention designed to influence their responses.

Correct

Answer:d.

In observational studies, subjects do not receive anyintervention designed to influence their responses.


All the following statements about parallel design are true except:

Answer

Selected

Answer:d.

Good if the intra-patients variability is relatively smallcompared to the inter-patients variability

Correct

Answer:d.




A design that is particularly relevant in situations where researchers are reluctant to depriveany subject of the intervention.Answer

Selected Answer:d.

Parallel with wait-List Control

Correct Answer:d.

Parallel with wait-List Control



Selected Answer: b.

False

Correct Answer: b.

False





Answer

Selected

Answer:a.


Correct

Answer:a.




Evaluation of efficacy and detection of rare or long-term adverse effects areachieved usingAnswer

Selected Answer:e.

phase IV trials

Correct Answer:e.

phase IV trials




following:Answer

Selected Answer:c.


Correct Answer:c.





Rigorous clinical trials, with proper attention to bias and chance, can be done

with individual patients, one at a time.Answer


Correct Answer:True



Selected Answer:d.

5

Correct Answer:d.

5


Investigators know the assignments of subjects in a randomized controlled trial. What might be

done to help avoid random (non-differential) misclassification of outcomes in the trial? Select

the best answer.Answer

Selected Answer:e.

Ask a blinded outcome assessment committee to assess outcomes.

Correct Answer:e.

Ask a blinded outcome assessment committee to assess outcomes.


Quasi-experimental studies are threatened by which of the following biases

Answer

Selected Answer:d.

History bias

Correct Answer:e.

All of the above




A trial that provides preliminary information on whether the drug is efficacious

and the relationship between dose and efficacy isAnswer

Selected Answer: e.

Phase I trial

Correct Answer:d.

Phase II trial


All the following are advantages of interrupted time series design except:Answer

Selected Answer:a.

Few data points are needed

Correct Answer:a.

Few data points are needed


All the followings are advantages of the before and after designs except:Answer

Selected

Answer:a.

Many characteristics of study population are identical in both phases

Correct

Answer: b.

No secular trends


All the following are advantages of interrupted time series except Answer

Selected Answer:c.

No history bias

Correct Answer:c.

No history bias




In a hospital-based clinical trial of the management of paranoid schizophrenia,

relief of symptoms in patients treated with a new drug is compared withsymptom relief among patients previously treated with a standard drug. Which

of the following may bias the analysis of the relative benefits of the new andstandard drugs?

Answer

Selected Answer:d.

All of the above

Correct Answer:d.

All of the above



Selected Answer:c.

a or b

Correct Answer:c.

a or b







Selection and attrition bias are the main disadvantages of interrupted timeseries design.Answer

Selected Answer:

FalseCorrect Answer:

False




The gold standard for evaluating innovation in health care isAnswer

Selected Answer:a.

Randomized controlled trial

Correct Answer:a.

Randomized controlled trial


Restricted Randomization includes Answer

Selected Answer:d.

All of the above

Correct Answer:d.

All of the above






A disadvantage of cross-over designAnswer

Selected Answer:e.

Carry over effects when occur are difficult to detect

Correct Answer:e.

Carry over effects when occur are difficult to detect











Selected Answer:c.

intention to treat

Correct Answer:c.

intention to treat


A treatment that is effective on the average is guaranteed to work on anindividual patients.Answer





Selected Answer:a.

No history bias

Correct Answer:a.

No history bias




A trial to identify a dose range that is well tolerated and safe and includes verysmall number of patients without a control group is

Answer

Selected Answer:d.

Phase II trial

Correct Answer:e.

Phase I trial


In parallel design, the treatment group is compared toAnswer

Selected Answer: d.

a or b or c

Correct Answer:d.

a or b or c




Selected Answer: e.


Correct Answer:e.



All the following for eligibility criteria are true except:Answer

Selected Answer:a.

Guaranteed benefit

Correct Answer:a.

Guaranteed benefit

!

Question!1!!

4!out!of!4!points!

! !



!

Clinical!trial!randomization!of!study!subjects!is!performed!to!reduce!the!

influence!of!

Answer!!!! !


Selection!bias!


Selection!bias!!

!! !

Question!2!!

4!out!of!4!points!

! !

!

What!is!the!key!difference!between!an!observational!study!and!an!experiment?!

Answer!!!! !

Selected!

Answer:!

!c.!!!

In!observational!studies,!subjects!do!not!receive!any!

intervention!designed!to!influence!their!responses.!

Correct!

Answer:!

!c.!!!

In!observational!studies,!subjects!do!not!receive!any!intervention!designed!to!influence!their!responses.!

!

!! !


! !

!

All!the!following!studies!are!observational!except:!

Answer!! !!!


quasiJexperimental!


quasiJexperimental!!

!! !

Question!4!!

4!out!of!4!points!

! !

!

All!the!following!biases!are!threat!to!pre!and!post!designs!except!Answer!! !!!


Selection!bias!


Selection!bias!!

!! !

Question!5!!

4!out!of!4!points!

! !

!

Crossover!design!is!less!efficient!than!parallel!design.!

Answer!! !!!





!! !

Question!6!!

0!out!of!4!points!

! !

!

It!is!difficult!to!perform!intentionJtoJtreat!analyses!with!randomized!controlled!trials.!!

Answer!!!! !



!! !

Question!7!!

4!out!of!4!points!

! !

!

A!clinical!trial!phase!where!investigators!conduct!a!full!scale!evaluation!of!treatment!

Answer!!!! !


Phase!III!


Phase!III!!

!! !

Question!8!!

4!out!of!4!points!

! !

!

Investigators!know!the!assignments!of!subjects!in!a!randomized!controlled!

trial.!What!might!be!done!to!help!avoid!random!(nonJdifferential)!misclassification!of!outcomes!in!the!trial?!Select!the!best!answer.!!

Answer!!

!! !

Selected!Answer:!

!b.!!!Ask!a!blinded!outcome!assessment!committee!to!assess!

outcomes.!!

Correct!Answer:!

!b.!!!Ask!a!blinded!outcome!assessment!committee!to!assess!

outcomes.!!!

!! !


! !

!

Selection!and!attrition!bias!are!the!main!disadvantages!of!interrupted!time!series!design.!

Answer!!!! !



!! !

Question!10!!

4!out!of!4!points!

! !



!

There!is!generally!an!increased!threat!to!the!internal!and!external!validity!of!

quasiJexperimental!study!compared!to!a!randomized!controlled!trial.!

Answer!!!! !



!! !

Question!11!!

4!out!of!4!points!

! !

!

Compared!to!RCT,!in!quasiJexperimental!design!

Answer!! !!!


Both!A!and!B!are!true!


Both!A!and!B!are!true!!

!! !

Question!12!!

4!out!of!4!points!

! !

!

All!the!following!for!eligibility!criteria!are!true!except:!

Answer!! !!!


Guaranteed!benefit!!

Correct!Answer:! !a.!!!Guaranteed!benefit!!

!

!! !

Question!13!!

4!out!of!4!points!

! !

!

The!gold!standard!for!evaluating!innovation!in!health!care!is!

Answer!! !!!


Randomized!controlled!trial!


Randomized!controlled!trial!!

!! !

Question!14!!

4!out!of!4!points!

! !

!

The!number!of!subjects!needed!for!phase!III!clinical!trial!is!usually!between!

Answer!! !!!


100!and!3000!


100!and!3000!!

!! !

Question!15!!



4!out!of!4!points!

! !

!

Quasi!experimental!study!design!can!also!be!used!in!situations!where!there!

are!practical!or!ethical!barriers!to!conducting!a!true!RCT.!!

Answer!!!! !



!! !

Question!16!!

4!out!of!4!points!

! !

!

Factorial!design!is!suitable!for!

Answer!! !!!


a!or!b!


a!or!b!!

!! !

Question!17!!

0!out!of!4!points!

! !

!

In!a!hospitalJbased!clinical!trial!of!the!management!of!paranoid!

schizophrenia,!relief!of!symptoms!in!patients!treated!with!a!new!drug!is!compared!with!symptom!relief!among!patients!previously!treated!with!a!

standard!drug.!Which!of!the!following!!may!bias!the!analysis!of!the!relative!

benefits!of!the!new!and!standard!drugs?!

Answer!!

!! !


None!of!the!above!Correct!Answer:! !d.!!!

All!of!the!above!!

!! !


! !

!

The!main!advantage!of!randomization!!

Answer!! !!!

Selected!

Answer:!

!a.!!!

Makes!balance!with!respect!to!known!and!unknown!

baseline!confounders!unlikely!

Correct!

Answer:!

!d.!!!

Assures!generalizability!of!results!to!a!wider!group!!

!! !

Question!19!!

4!out!of!4!points!

! !

!

Phase!II!trials!are!used!to!determine!a!safe!dose!!

Answer!! !!!




False!


False!!

!! !


! !

!

All!the!following!statements!about!phase!II!trials!are!true!except:!!

Answer!! !!!

Selected!Answer:! !b.!!!Usually!recruit!mor!than!100!subjects!


Usually!recruit!mor!than!100!subjects!!

!! !

Question!21!!


!

A!clinical!trial!phase!where!investigators!initially!evaluate!how!well!the!

treatment!works!!

Answer!!!! !


Phase!II!


Phase!II!!

!! !

Question!22!!


!

Blocking!ensures!close!balance!of!the!numbers!in!each!group!at!all!times!

during!trial.!!!Answer!!

!! !



!! !

Question!23!!

4!out!of!4!points!

! !

!

Evaluation!of!efficacy!and!detection!of!rare!or!longJterm!adverse!effects!are!

achieved!using!

Answer!! !! !

Selected!Answer:! !e.!!!phase!IV!trials!


phase!IV!trials!!

!! !

Question!24!!



4!out!of!4!points!

! !

!

A!design!that!is!particularly!relevant!in!situations!where!researchers!are!

reluctant!to!deprive!any!subject!of!the!intervention.!

Answer!!!! !

Selected!Answer:! !d.!!!Parallel!with!waitJList!Control!

Correct!Answer:! !d.!!!Parallel!with!waitJList!Control!

!

!! !

Question!25!!

4!out!of!4!points!

! !

!

All!the!followings!are!advantages!of!the!before!and!after!designs!except:!

Answer!! !!!


No!secular!trends!!


No!secular!trends!!!

!! !

Question!26!!

4!out!of!4!points!

! !

!

QuasiJexperimental!studies!are!threatened!by!which!of!the!following!biases!!Answer!! !!!


All!of!the!above!

Correct!Answer:! !e.!!!All!of!the!above!

!

!! !

Question!27!!

4!out!of!4!points!

! !

!

Parallel!designs!are!good!if!the!intraJsubjects!variability!relatively!small!compared!to!the!interJsubjects!variability.!!!

Answer!!!! !



!! !


! !

!

Pre–post!designs!with!no!control!group!is!the!most!commonly!encountered!

quasiJexperimental!designs.!!!!

Answer!!!! !



!! !



Question!29!!

4!out!of!4!points!

! !

!

All!the!following!statements!about!parallel!design!are!true!except:!

Answer!! !!!

Selected!Answer:! !d.!!!Good!if!the!intraJpatients!variability!is!relatively!small!

compared!to!the!interJpatients!variability!

Correct!

Answer:!

!d.!!!

Good!if!the!intraJpatients!variability!is!relatively!small!

compared!to!the!interJpatients!variability!!

!! !

Question!30!!

4!out!of!4!points!

! !

!

Bias!due!to!differences!in!reporting!of!symptoms!between!treatment!groups!

Answer!! !!!


Information!bias!


Information!bias!!

!! !

!

!

Question!1!!

4!out!of!4!points!

! !

!

All!the!following!are!advantages!of!interrupted!time!series!design!except:!

Answer!! !!!

Selected!Answer:! !a.!!!Few!data!points!are!needed!


Few!data!points!are!needed!!

!! !

Question!2!!

4!out!of!4!points!

! !

!

Which!the!following!actions!are!most!likely!to!preserve!the!benefit!of!initial!

randomization!in!a!clinical!trial!comparing!different!weight!loss!programs?!

Answer!!

!! !


Blinding!of!the!clinicians!who!evaluate!weight!loss!


Blinding!of!the!clinicians!who!evaluate!weight!loss!!

!! !


! !



!

Why!is!randomization!important!to!assignment!in!a!randomized!clinical!

trial?!

Answer!!!! !


a!and!c!


a!and!c!!

!! !

Question!4!!

4!out!of!4!points!

! !

!

Preclinical!animal!studies!are!known!as!phase!0!studies!!Answer!! !!!


True!

Correct!Answer:! !a.!!!True!

!

!! !

Question!5!!

4!out!of!4!points!

! !

!

A!treatment!that!is!effective!on!the!average!is!guaranteed!to!work!on!an!

individual!patients.!

Answer!!!! !



!! !

Question!6!!

4!out!of!4!points!

! !

!

All!the!following!are!true!in!a!randomized!control!trial!(RCT)!except:!Answer!! !!!


The!sample!size!required!depends!on!the!hypothesis!


The!sample!size!required!depends!on!the!hypothesis!!

!! !

Question!7!!

4!out!of!4!points!

! !

!

Compared!to!parallel!design,!power!of!simple!comparison!may!be!greater!with!factorial!design.!

Answer!!!! !



!! !

Question!8!!

4!out!of!4!points!



! !

!

Data!and!safety!monitoring!board!deals!only!with!current!study!participants!!!Answer!! !!!



!! !


! !

!

A!trial!to!identify!a!dose!range!that!is!well!tolerated!and!safe!and!includes!

very!small!number!of!patients!without!a!control!group!is!!

Answer!!!! !


Phase!I!trial!


Phase!I!trial!!

!! !


! !

!

An!advantage!of!analysis!by!"intention!to!treat"!is!that!It!is!not!affected!by!patients!dropping!out!of!the!study.!!!!

Answer!!!! !



!! !

Question!11!!

4!out!of!4!points!

! !

!

Always!analyze!the!results!of!the!subjects!according!to!the!group!they!were!

randomized!to.!This!type!of!analysis!is!known!as!Answer!!

!! !


Intention!to!treat!analysis!


Intention!to!treat!analysis!!

!! !

Question!12!!

4!out!of!4!points!

! !

!

Phase!II!trials!are!used!to!determine!a!safe!dose!!

Answer!! !!!


False!


False!!

!! !

Question!13!!



4!out!of!4!points!

! !

!

People!have!a!tendency!to!change!their!behavior!when!they!are!the!target!of!

special!interest!and!attention!in!a!study,!regardless!of!the!specific!nature!of!

the!intervention!they!might!be!receiving.!This!phenomenon!is!called!

Answer!!

!! !


Hawthorne!effect!


Hawthorne!effect!!

!! !

Question!14!!

4!out!of!4!points!

! !

!

Evaluation!of!efficacy!and!detection!of!rare!or!longJterm!adverse!effects!are!achieved!using!

Answer!!!! !


phase!IV!trials!


phase!IV!trials!!

!! !

Question!15!!

4!out!of!4!points!

! !

!

All!the!followings!are!advantages!of!the!before!and!after!designs!except:!

Answer!! !!!


No!secular!trends!!


No!secular!trends!!!

!! !

Question!16!!

4!out!of!4!points!

! !

!

Parallel!designs!are!good!if!the!intraJsubjects!variability!relatively!small!

compared!to!the!interJsubjects!variability.!!!

Answer!!!! !



!! !

Question!17!!

4!out!of!4!points!

! !

!

Trials!that!compare!efficacy!of!the!new!treatment!with!the!standard!

treatment!are!!Answer!!

!! !




phase!III!


phase!III!!

!! !


! !

!

A!disadvantage!of!crossJover!design!!

Answer!! !!!

Selected!Answer:! !e.!!!Carry!over!effects!when!occur!are!difficult!to!detect!


Carry!over!effects!when!occur!are!difficult!to!detect!!

!! !

Question!19!!


!

Total!number!of!phases!in!clinical!trials!

Answer!! !!!

Selected!Answer:! !d.!!!5!


5!!

!! !

Question!20!!

4!out!of!4!points!

! !

!

Researchers!want!to!assess!if!there!is!an!association!between!cigarette!smoking!and!strokes.!Of!the!following,!which!is!the!best!study!design!to!

assess!for!this!association?!!Answer!!

!! !


Prospective!cohort!study!!


Prospective!cohort!study!!!

!! !

Question!21!!


!

Quasi!experimental!study!design!can!also!be!used!in!situations!where!there!

are!practical!or!ethical!barriers!to!conducting!a!true!RCT.!!

Answer!!!! !



!! !

Question!22!!



4!out!of!4!points!

! !

!

There!is!generally!an!increased!threat!to!the!internal!and!external!validity!of!

quasiJexperimental!study!compared!to!a!randomized!controlled!trial.!

Answer!!!! !



!! !

Question!23!!

4!out!of!4!points!

! !

!

IntentionJtoJtreat!analysis!entails!analyzing!the!results!without!regard!to!

subject!compliance.!!!

Answer!!!! !



!! !

Question!24!!


!

Researchers!want!to!assess!if!there!is!an!association!between!cocaine!use!

and!congestive!heart!failure.!Select!the!correct!statement:!!

Answer!!!! !

Selected!

Answer:!

!a.!!!

The!researchers!should!be!concerned!about!recall!bias!if!they!choose!to!perform!a!retrospective!cohort!study.!!

Correct!

Answer:!

!e.!!!

The!researchers!should!be!concerned!about!reporting!bias!if!

they!conduct!a!case!control!study.!!!

!! !


! !

!

A!weakness!of!randomized!controlled!trials!is!that!they!are!prone!to!

misclassification!of!exposure!status.!!

Answer!!!! !



!! !

Question!26!!

4!out!of!4!points!

! !

!

Always!analyze!the!results!of!the!subjects!according!to!the!group!they!were!randomized!to.!This!method!is!known!as!!

Answer!!!! !

Selected!Answer:! !c.!!!intention!to!treat!

Correct!Answer:! !c.!!!!! !



intention!to!treat!!

Question!27!!

4!out!of!4!points!

! !

!

The!number!of!subjects!needed!for!phase!I!clinical!trial!is!between!

Answer!! !!!


20!and!80!


20!and!80!!

!! !

Question!28!!

4!out!of!4!points!

! !

!

A!design!used!to!test!for!Interaction!!

Answer!! !!!

Selected!Answer:! !b.!!!Factorial!!!


Factorial!!!!

!! !

Question!29!!

4!out!of!4!points!

! !

!

A!design!that!is!particularly!relevant!in!situations!where!researchers!are!

reluctant!to!deprive!any!subject!of!the!intervention.!

Answer!!!! !

Selected!Answer:! !a.!!!Parallel!with!waitJList!Control!


Parallel!with!waitJList!Control!!

!! !

Question!30!!

4!out!of!4!points!

! !

!

In!parallel!design,!the!treatment!group!is!compared!to!Answer!! !!!


a!or!b!or!c!

Correct!Answer:! !d.!!!a!or!b!or!c!

!

!! !

Thursday,!March!14,!2013!7:42:04!PM!EDT!

OK!!

!




Factorial design is suitable for testing for Interaction.Answer


Correct Answer:True


Clinical trial randomization of study subjects is performed to reduce theinfluence of Answer

Selected Answer:c.

Selection bias

Correct Answer:c.

Selection bias



Selected Answer: b.

False

Correct Answer: b.

False• Question 4

0 out of 4 points





Intention-to-treat analysis entails analyzing the results without regard tosubject compliance.Answer


Correct Answer:True





Selected Answer:d.

No history bias

Correct Answer:d.

No history bias


All the following are true in a randomized control trial (RCT) except:Answer

Selected

Answer:c.

Baseline characteristics of intervention and control groups should be

similar

Correct Answer:a.

The sample size required depends on the hypothesis


An advantage of analysis by "intention to treat" is thatAnswer

Selected

Answer:d.



Correct

Answer:d.












Answer

Selected

Answer:a.


Correct

Answer:a.




All the following are advantages of parallel designs with historical controlexcept Answer

Selected Answer:e.


Correct Answer:e.




Selected Answer:c.

a or b

Correct Answer:c.

a or b









All the following statements about parallel design are true except:Answer

SelectedAnswer:

e.

Each subject is randomized to one and only one treatment.

Correct

Answer:d.




All the following studies are observational except:Answer

Selected Answer: b.

case-control

Correct Answer:d.

quasi-experimental


Compared to RCT, in quasi-experimental designAnswer

Selected Answer:c.


Correct Answer:c.



A weakness of randomized controlled trials is that they are prone to misclassification of

exposure status.Answer






As heterogeneity is restricted, the internal validity of the study is improved.Answer


Correct Answer:True




Selected Answer: b.

blinded analysis

Correct Answer: c.

intention to treat


Incomplete follow-up in clinical trials Answer

Selected Answer:c.

Will always bias results but direction unclear

Correct Answer: b.

May be a cause of bias



Selected Answer:d.

5

Correct Answer:d.

5




In a hospital-based clinical trial of the management of paranoid schizophrenia,relief of symptoms in patients treated with a new drug is compared with

symptom relief among patients previously treated with a standard drug. Whichof the following may bias the analysis of the relative benefits of the new and

standard drugs? Answer

Selected

Answer: b.

Changes over time in the methods used to assess symptom

relief

Correct Answer:d.

All of the above


Quasi experimental study design can also be used in situations where there are practical or ethical barriers to conducting a true RCT.Answer


Correct Answer:True


A clinical trial phase where investigators initially evaluate how well the

treatment works Answer

Selected Answer:a.

Phase II

Correct Answer:a.

Phase II


Parallel designs are good if the intra-subjects variability relatively small

compared to the inter-subjects variability.Answer






When participants are repeatedly observed using the same ‘test’, there is a possibility of learning effect and this could lead to

Answer

Selected Answer: b.

Testing bias

Correct Answer: b.

Testing bias




following:Answer

Selected Answer:d.

A and B

Correct Answer:c.





Selected Answer: b.


Correct Answer: b.



There is generally an increased threat to the internal and external validity of quasi-experimental study compared to a randomized controlled trial.Answer


Correct Answer:True




What is the key difference between an observational study and an experiment? Answer

SelectedAnswer:

d.

In observational studies, subjects do not receive any

intervention designed to influence their responses.

Correct

Answer:d.

In observational studies, subjects do not receive anyintervention designed to influence their responses.

!



Question)1))

4)out)of)4)points)

) )

)

In)the)British)doctors)study,)over)40)years)of)follow)up,)the)annual)mortality)rate)from)CHD)was)

572)per)100)000)in)nonsmokers,)and)892)per)100)000)in)smokers.))For)lung)cancer)the)figures)were)14)and)209,)respectively.)So,)a)comparatively)small)increase)in)risk)of)CHD,)associated)with)

smoking,)results)in)a)large)number)of)deaths.)))

Answer))

)) )



)

)) )

Question)2))

0)out)of)4)points)

) )

)

A)high)blood)pressure)today)is)a)poor)predictor)of)its)future)rate)of)rise.))

Answer)) )) )



)

)) )

Question)3))

4)out)of)4)points)

) )

)

Exposure) ))))))))))))))))Outcome) Total)

Yes) No)

Yes) 80) 20) 100)

No) 50) 50) 100)

Total) 130) 70) 200)

The)odds)ratio=)

Answer))

)) )




4)


4)

)

)) )

Question)4))

4)out)of)4)points)

) )

)

))

Smoke)

)))))))Develop))CHD) ))

Total))Yes) ))No)

Yes) 30) )))70) 100)

No) 30) )270) 300)

Total) 60) )240) 400)

Risk)among)smokers))

Answer))

)) )


0.3)


0.3)

)

)) )

Question)5))

4)out)of)4)points)

) )

)


572)per)100)000)in)nonsmokers,)and)892)per)100)000)in)smokers.))For)lung)cancer)the)figures)

were)14)and)209,)respectively.)Therefore)for)an)individual,)smoking)was)much)more)likely)to)

result)in)death)from)lung)cancer)than)from)CHD.))

Answer))

)) )





)

)) )

Question)6))

0)out)of)4)points)

) )

)

For)a)heavy)smoker,)the)probability)of)getting)lung)cancer)in)the)next)10)years)is))

Answer)) )) )


15%)


10%)

)

)) )

Question)7))

4)out)of)4)points)

) )

)

The)excess)incidence)of)disease)in)a)community)that)is)associated)with)a)risk)factor))

Answer)) )) )


population)attributable)risk))



)

)) )

Question)8))

4)out)of)4)points)

) )

)

Cohort)study)establishes)time)sequence)for)causality)

Answer)) )) )




True)


True)

)

)) )

Question)9))

4)out)of)4)points)

) )

)

Just)because)risk)factors)predict)disease,)it)does)not)necessarily)follow)that)they)cause)disease.)

Answer)) )) )


True)


True)

)

)) )

Question)10))

0)out)of)4)points)

) )

)

A)heavy)smoker)has)at)least)a)hundred)fold)greater)risk)of)lung)cancer)compared)to)

nonsmokers.)

Answer)))) )



)

)) )

Question)11))

4)out)of)4)points)

) )

)



were)14)and)209,)respectively.)So,)smoking)is)associated)with)a)larger)attributable)risk)for)CHD))) )



than)for)lung)cancer.)))

Answer))



)

)) )

Question)12))

0)out)of)4)points)

) )

)

All)the)followings)are)disadvantages)of)crosssectional)studies)except)

Answer)) )) )

Selected)

Answer:)

)a.)))

Difficult)to)separate)cause)from)effect,)because)measurement)of)exposure)and)

disease)is)conducted)at)the)same)time.))

Correct)

Answer:)

)b.)))

Always)less)generalizable)than)cohort)due)to)the)use)of)populationbased)

samples,)instead)of)convenient)samples.))

)

)) )

Question)13))

0)out)of)4)points)

) )

)

In)the)investigation)of)an)epidemic)of)a)fatal)disease)such)as)SARS,)the)most)appropriate)

measure)to)describe)the)frequency)of)death)from)the)disease)is)the:)

Answer)))) )


Mortality)rate)


Casefatality)rate)

)

)) )

Question)14))



4)out)of)4)points)

) )

)

)Exposure) ))))))))))))))))Outcome) )Total)

Yes) No)

Yes) 80) 20) 100)

No) 50) 50) 100)

Total) 130) 70) 200)

Relative)Risk=)

Answer))

)) )


1.6)


1.6)

)

)) )

Question)15))

4)out)of)4)points)

) )

)

Consider)a)study)of)1000)people)in)which)500)are)treated)with)a)new)drug)and)500)are)treated)

with)placebo.)If)5)in)the)treatment)group)(1%)and)10)in)the)placebo)group)(2%)have)heart)

attacks,)the)relative)risk)of)heart)attack)with)treatment)would)be)

Answer))

)) )


0.5))


0.5))

)

)) )

Question)16))

4)out)of)4)points)

) )



)

))

)

Smoke)


)

Total)

))Yes) ))No)

Yes) ))10) )))90) 100)

No) )))5) )))95) 100)

Total) )15) )185) 200)

Risk)among)smokers=)

Answer))

)) )

Selected)Answer:) )) ))

0.1)

Correct)Answer:) ))))

0.1)

)

)) )

Question)17))

4)out)of)4)points)

) )

)

The)strength)of)an)association)between)exposure)and)disease)is)best)measured)by)the:)

Answer)) )) )


Relative)risk)


Relative)risk))

)) )

Question)18))

4)out)of)4)points)

) )

)

Measure)of)the)potential)for)prevention)of)disease)if)the)exposure)could)be)eliminated))

)) )



Answer))


attributable)rsk)


attributable)rsk)

)

)) )

Question)19))

4)out)of)4)points)

) )

)

Which)of)the)following)study)design)(s)can)be)done)on)a)sample)of)the)population?)

Answer)) )) )


Both)c)&)d)


Both)c)&)d)

)

)) )

Question)20))

0)out)of)4)points)

) )

)

Measures)of)absolute,)attributable,)and)relative)risks)are)less)frequently)encountered)in)the)

clinical)literature)than)are)measures)of)population)risk.))

Answer)))) )



)

)) )

Question)21))

4)out)of)4)points)

) )

)

Most)studies)of)risk)are)observational)studies)and)are)either)crosssectional)or)case)series))

)) )



Answer))


False)


False)

)

)) )

Question)22))

4)out)of)4)points)

) )

)



were)14)and)209,)respectively.)So,)smoking)has)a)much)stronger)association)with)CHD)than)lung)

cancer.))))

Answer))

)) )



)

)) )

Question)23))

0)out)of)4)points)

) )

)

All)the)following)statements)are)true)except)

Answer)) )) )

Selected)

Answer:)

)b.)))

Knowledge)of)risk)factors)can)be)used)to)improve)the)efficiency)of)screening)

programs.)

Correct)

Answer:)

)c.)))

If)a)risk)factor)is)a)cause)of)a)disease),)removing)it)is)not)necessary)to)prevent)

the)disease.)

)

)) )

Question)24))



0)out)of)4)points)

) )

)

I.)Exposure)measured)before)the)development)of)disease)II.)Exposure)measured,)reconstructed,)

or)recollected)after)development)of)disease)III.)Exposure)measured,)at)the)same)time)as)

disease.)In)cohort)studies)exposure)assessment)is)true)for))

Answer)))) )


I)&)II)


I))

)

)) )

Question)25))

4)out)of)4)points)

) )

)

))

)

Smoke)


)

Total)

))Yes) ))No)

Yes) ))10) )))90) 100)

No) )))5) )))95) 100)

Total) )15) )185) 200)

Risk)among)nonsmokers=)

Answer))

)) )


0.05)


0.05)

)

)) )

Question)26))



4)out)of)4)points)

) )

)

The)excess)incidence)of)disease)in)a)community)that)is)associated)with)a)risk)factor))

Answer)) )) )





)

)) )

Question)27))

4)out)of)4)points)

) )

)

If)we)assume)that)the)relative)risk)reduction)associated)with)statin)treatment)is)33%,)in)patients)

with)an)initial)risk)of)30%)the)absolute)risk)will)be)reduced)from)30%)to)

Answer)))) )


20%)


20%)

)

)) )

Question)28))

0)out)of)4)points)

) )

)

Researchers)are)interested)in)assessing)a)possible)association)between)a)rare)exposure)and)a)

reduction)of)bone)mineral)density.)The)best)study)design)to)assess)this)possible)association)is:))

Answer)))) )


a)case)control)study)) )) )




a)prospective)cohort)study))

)

Question)29))

4)out)of)4)points)

) )

)

Relative)risk)is)the)basic)expression)of)risk.))

Answer)) )) )



)

)) )

Question)30))

4)out)of)4)points)

) )

)

All)the)followings)are)strengths)of)cohort)studies)except)

Answer)) )) )


Can)measure)multiple)exposures)


Can)measure)multiple)exposures)

)

)) )


For absolute risk reduction of 5%, the NNT is

Answer

Selected Answer:

c.20

Correct Answer:c.

20




Researchers are interested in assessing a possible association between statin and a raredisease. The best study design to assess this possible association is:

Answer

Selected Answer:d.

a prospective cohort study

Correct Answer:e.

a case control study


Smoke

Develop CHD

Total

Yes No

Yes 10 90 100

No 5 95 100

Total 15 185 200

Risk among nonsmokers=

Answer

Selected Answer:a.

0.05

Correct Answer:a.

0.05

• • Question 4

0 out of 4 points

The basic expression of risk isAnswer

Selected Answer:d.

prevalence

Correct Answer:c.

incidence




Smoke

Develop CHD

Total Yes No

Yes 30 70 100

No 30 270 300

Total 60 240 400

Risk among smokers

Answer

Selected Answer: b.

0.3

Correct Answer: b.

0.3


In the British doctors study, over 40 years of follow up, the annual mortality rate from

CHD was 572 per 100 000 in non-smokers, and 892 per 100 000 in smokers. For lungcancer the figures were 14 and 209, respectively. So, smoking has a much stronger

association with CHD than lung cancer.Answer




Smoke

Develop CHD

Total Yes No

Yes 30 70 100

No 30 270 300

Total 60 240 400

Risk difference=

Answer

Selected Answer:d.

0.15Correct Answer:

e.

0.2




Smoke

Develop CHD

Total Yes No

Yes 50 50 100

No 20 280 300

Total 70 230 400

Attibutable Risk Percent (AR%)=Answer

Selected Answer:d.

60%

Correct Answer:

d.60%


A study reported the association between obesity and colon cancer morbidity asdetermined from review of medical records and death certificates in a nationally

representative cohort of men and women age 25-74 years who participated in the First National Health and Nutrition Examination Survey from 1971 to 1975 and were

subsequently followed up through 1992. Which research design has been used in thisstudy?Answer

Selected Answer: b.

Prospective cohort

Correct Answer: b.

Prospective cohort


All the followings are strengths of cohort studies exceptAnswer

Selected Answer: b.

Provides incidence data

Correct Answer:a.

Can study rare outcomes





cancer the figures were 14 and 209, respectively. Therefore for an individual, smokingwas much more likely to result in death from lung cancer than from CHD.Answer




Cohort study establishes time sequence for causalityAnswer

Selected Answer:

a.True

Correct Answer:a.

True


Risk cannot be estimated directly from a case–control study.Answer




What research design is used for patient survey research?Answer

Selected Answer:d.

cross sectional study

Correct Answer:d.

cross sectional study




RR is basicallyAnswer

Selected Answer: c.

Relative Risk

Correct Answer:c.

Relative Risk


Smoke

Develop CHD

Total Yes No

Yes 10 90 100

No 15 285 300

Total 25 375 400

Incidence of CHD among nonsmokers

Answer

Selected Answer:d.

50 per 1000

Correct Answer:d.

50 per 1000

• Question 17

4 out of 4 points

Exposure Outcome Total

Yes No

Yes 80 20 100

No 50 50 100

Total 130 70 200

The odds ratio=

Answer

Selected Answer:c.

4

Correct Answer:c.

4




Uses of risk Answer

Selected Answer: d.

all of the above

Correct Answer:d.

all of the above


Smoke

Develop CHD

Total Yes No

Yes 10 90 100

No 15 285 300

Total 25 375 400

Incidence of CHD among smokers

Answer

Selected Answer:a.

100 per 1000

Correct Answer:a.

100 per 1000

• Question 20

4 out of 4 points

Smoke

Develop CHD

Total Yes No

Yes 30 70 100

No 30 270 300

Total 60 240 400

Risk among nonsmokers

Answer

Selected Answer:a.

0.1

Correct Answer:a.

0.1




The additional risk of disease following Exposure, over and above that experienced by people who are not exposed is called

Answer

Selected Answer:c.

attributable risk

Correct Answer:c.

attributable risk


Consider a study of 1000 people in which 500 are treated with a new drug and 500 are treated with placebo.

If 5 in the treatment group (1%) and 10 in the placebo group (2%) have heart attacks, the relative risk of heart

attack with treatment would be

Answer

Selected Answer:c.

0.5

Correct Answer:c.

0.5






The prevalence of a disease at a point in time is a function of Answer

Selected Answer:e.

A & C

Correct Answer:d.

a and b




When data are combined from smaller studies into a larger sample size, which canthen be statistically evaluated in a more robust fashion than the smaller samples, the

following term is appliedAnswer

Selected Answer:d.

meta-analysis

Correct Answer:d.

meta-analysis


All the following statements are true except

Answer

Selected

Answer:a.


Correct

Answer:a.

If a risk factor is a cause of a disease , removing it is not necessary to

prevent the disease.


For absolute risk reduction of 1%, the NNT is Answer

Selected Answer: b.

100

Correct Answer: b.

100


Measure of the potential for prevention of disease if the exposure could be eliminatedAnswer

Selected Answer:a.

attributable rsk

Correct Answer:a.

attributable rsk




In a series of 1000 women with breast cancer, 32 were pregnant. From this we canconclude:

Answer

Selected

Answer:c.

In this particular series of women with breast cancer, 3.2% were pregnant

Correct Answer:c.

In this particular series of women with breast cancer, 3.2% were

pregnant


Researchers are interested in assessing a possible association between a rare exposureand a reduction of bone mineral density. The best study design to assess this possible

association is: Answer

Selected Answer:a.


Correct Answer:a.


• Question 1

4 out of 4 points

Multiple sclerosis (MS) has an overall incidence rates in the US of less than one tenthof that of lung cancer. Yet the prevalence rate of MS is much higher than that of lung

cancer. Possible explanation isAnswer

Selected Answer: b.

duration of lung cancer is shorter than multiple sclerosis

Correct Answer: b.

duration of lung cancer is shorter than multiple sclerosis




Incidence studies are also called

Answer

Selected Answer: a.

prospective studies

Correct Answer:e.

a and b


The incidence of the disease among the unexposed group is 5 per 1000. The relative

risk of the disease is 5. What is the incidence of the disease among the unexposed?

Answer

Selected Answer:d.

25 per thousand

Correct Answer:d.

25 per thousand


Smoke

Develop CHD

Total Yes No

Yes 10 90 100

No 15 285 300

Total 25 375 400

Incidence of CHD among smokers

Answer

Selected Answer:c.

100 per 1000

Correct Answer:c.

100 per 1000





Yes No

Yes 80 20 100

No 50 50 100

Total 130 70 200

The odds ratio=

Answer

Selected Answer:a.

4

Correct Answer:a.

4



cancer the figures were 14 and 209, respectively. So, a comparatively small increasein risk of CHD, associated with smoking, results in a large number of deaths.Answer


Correct Answer:True


Smoke

Develop CHD

Total Yes No

Yes 50 50 100

No 20 280 300

Total 70 230 400

Attibutable Risk Percent (AR%)=Answer

Selected Answer:a.

60%

Correct Answer:a.

60%




In the investigation of an epidemic of a fatal disease such as SARS, the mostappropriate measure to describe the frequency of death from the disease is the:

Answer

Selected Answer: b.

Case-fatality rate

Correct Answer: b.

Case-fatality rate



Yes No

Yes 80 20 100

No 50 50 100

Total 130 70 200

Relative Risk=

Answer

Selected Answer:a.

1.6

Correct Answer:a.

1.6


Most studies of risk are observational studies and are either cross-sectional or case

seriesAnswer

Selected Answer: b.

False

Correct Answer: b.

False




I. Exposure measured before the development of disease II. Exposure measured,reconstructed, or recollected after development of disease III. Exposure measured, at

the same time as disease In cross-sectional studies exposure assessment is true for Answer

Selected Answer:c.

III

Correct Answer:c.

III


In the British doctors study, over 40 years of follow up, the annual mortality rate from

CHD was 572 per 100 000 in non-smokers, and 892 per 100 000 in smokers. Therelative risk Answer

Selected Answer:a.

320 per 100 000

Correct Answer:d.

1.6


Smoke

Develop CHD

Total Yes No

Yes 30 70 100

No 30 270 300

Total 60 240 400

Risk among nonsmokers

Answer

Selected Answer: b.

3

Correct Answer: a.0.1




All of the following are true for risk except:Answer

SelectedAnswer:

d.

The risk following inaction is perceived as smaller than the same risk

following action

Correct

Answer:d.

The risk following inaction is perceived as smaller than the same risk following action


All the followings are strengths of cohort studies except

Answer

Selected Answer:a.

Can study rare exposures

Correct Answer:c.

Can study rare outcomes


All the followings are strengths of cohort studies exceptAnswer

Selected Answer:d.

Can measure multiple exposures

Correct Answer:d.

Can measure multiple exposures


The additional risk of disease following Exposure, over and above that experienced by people who are not exposed is calledAnswer

Selected Answer:c.

attributable risk

Correct Answer:c.

attributable risk




If a condition is rare the importance of reducing risk is much lower than if it iscommon.


False

Correct Answer:True






A heavy smoker has at least a hundred fold greater risk of lung cancer compared to

nonsmokers.Answer


Correct Answer:True


For a heavy smoker, the probability of getting lung cancer in the next 10 years isAnswer

Selected Answer:c.

10%

Correct Answer:c.

10%


Cohort study establishes time sequence for causalityAnswer

Selected Answer:a.

True

Correct Answer:a.

True




The fraction of disease occurrence in a population that is associated with a particular risk factor

Answer

Selected Answer: b.

population attributable fraction

Correct Answer: b.

population attributable fraction


Most studies of risk are experimental studies.Answer




Measure of the potential for prevention of disease if the exposure could be eliminatedAnswer

Selected Answer:a.

attributable rsk

Correct Answer:

a.attributable rsk


Population attributable fraction is the fraction of disease occurrence in a population

that is associated with a particular risk factor. Answer


Correct Answer:True




The design where exposure status and disease status are measured at one point in timeor over a period is

Answer

Selected Answer:d.

cross-sectional

Correct Answer:d.

cross-sectional


Smoke

Develop CHD

Total

Yes No

Yes 10 90 100

No 5 95 100

Total 15 185 200

Relative risk=

Answer

Selected Answer:d.

0.5

Correct Answer: a.

2


A design well suited for studying symptoms and signs of a disease isAnswer

Selected Answer:e.

clinical trial

Correct Answer:a.

case series




Risk ratio is a measure of the potential for prevention of disease if the exposure could be eliminated.


False


!Question)1))

4)out)of)4)points)

) )

)


572)per)100)000)in)nonsmokers,)and)892)per)100)000)in)smokers.))The)relative)risk)))

Answer)))) )

Selected)Answer:) )d.)) )

1.6)


1.6)

)

)) )

Question)2))

4)out)of)4)points)

) )

)

Relative)risk)is)the)additional)risk)of)disease)following)Exposure,)over)and)above)that)

experienced)by)people)who)are)not)exposed.)

Answer)))) )



)

)) )

Question)3))

0)out)of)4)points)

) )



)

The)effect)of)most)risk)factors)in)human)cannot)be)studied)with)experimental)studies.)

Answer)) )) )



)

)) )

Question)4))

0)out)of)4)points)

) )

)

The)prevalence)of)a)disease)at)a)point)in)time)is)a)function)of)incidence)and)duration.)

Answer)) )) )



)

)) )

Question)5))

0)out)of)4)points)

) )

)

Which)of)the)following)study)designs)allow)direct)estimation)of)incidence)in)exposed)and)

unexposed)people?))

Answer)))) )


Both)A)&)D)


cohort)

)

)) )

Question)6))

4)out)of)4)points)

) )

)

What)research)design)is)used)for)patient)survey)research?)

Answer)) )) )




cross)sectional)study)


cross)sectional)study)

)

)) )

Question)7))

4)out)of)4)points)

) )

)

A)low)ventilatory)function)today)is)the)best)predictor)of)its)future)rate)of)decline.)

Answer)) )) )



)

)) )

Question)8))

4)out)of)4)points)

) )

)


14)per)100)000)in)nonsmokers,)and)209)per)100)000)in)smokers.)))The)relative)risk)))

Answer)) )) )


14.9)


14.9)

)

)) )

Question)9))

4)out)of)4)points)

) )

)

)))

)) )))))))Develop))CHD) )) )) )



Smoke) ))Yes) ))No) Total)

Yes) 50) )))50) 100)

No) 20) )280) 300)

Total) 70) )230) 400)

)

Attibutable)Risk)Percent)(AR%=))

Answer))


60%)


60%)

)

)) )

Question)10))

4)out)of)4)points)

) )

)

Measure)of)the)potential)for)prevention)of)disease)if)the)exposure)could)be)eliminated))

Answer)) )) )


attributable)rsk)


attributable)rsk)

)

)) )

Question)11))

4)out)of)4)points)

) )

)

))

)


))Yes) ))No) )) )



Smoke) Total)

Yes) ))10) )))90) 100)

No) )))5) )))95) 100)

Total) )15) )185) 200)

Risk)among)smokers=)

Answer))

Selected)Answer:) ))) )

0.1)

Correct)Answer:) ))))

0.1)

)

)) )

Question)12))

4)out)of)4)points)

) )

)

))

Smoke)


Total))Yes) ))No)

Yes) 30) )))70) 100)

No) 30) )270) 300)

Total) 60) )240) 400)

Risk)among)smokers))

Answer))

)) )


0.3)


0.3)

)

)) )



Question)13))

4)out)of)4)points)

) )

)

))

Smoke)


Total))Yes) ))No)

Yes) 10) )))90) 100)

No) 15) )285) 300)

Total) 25) )375) 400)

Incidence)of)CHD)among)nonsmokers)

Answer))

)) )


50))per))1000)


50))per))1000)

)

)) )

Question)14))

0)out)of)4)points)

) )

)

The)presence)of)a)strong)risk)factor)indicates)that)an)individual)is)very)likely)to)get)the)disease)

Answer)) )) )

Selected)Answer:) )b.)) )

True)


False)

)

)) )

Question)15))

4)out)of)4)points)

) )



)

A)heavy)smoker)has)at)least)a)hundred)fold)greater)risk)of)lung)cancer)compared)to)

nonsmokers.)

Answer)))) )



)

)) )

Question)16))

4)out)of)4)points)

) )

)

Uses)of)risk)

Answer)) )) )


all)of)the)above))


all)of)the)above))

)

)) )

Question)17))

4)out)of)4)points)

) )

)

Early)coronary)heart)disease)is)better)than)cholesterol,)blood)pressure,)smoking,)diabetes,)and)

obesity)as)predictor)of)future)fatal)disease.)

Answer)))) )



)

)) )

Question)18))

4)out)of)4)points)

) )

)

A))measure)suitable)for)policy)decision)

)) )



Answer))


attributable)risk)


attributable)risk)

)

)) )

Question)19))

4)out)of)4)points)

) )

)

Most)studies)of)risk)are)observational)studies)and)are)either)crosssectional)or)case)series))

Answer)) )) )


False)


False)

)

)) )

Question)20))

4)out)of)4)points)

) )

)

))

)

Smoke)


)

Total)

))Yes) ))No)

Yes) ))10) )))90) 100)

No) )))5) )))95) 100)

Total) )15) )185) 200)

Risk)among)nonsmokers=)

Answer))

)) )




0.05)


0.05)

)

)) )

Question)21))

4)out)of)4)points)

) )

)

A)study)design)for)which)cases)with)the)disease)in)question)are)matched)with)appropriate)

controls)(without)the)disease)in)question)is)called))

Answer)))) )


casecontrol)


casecontrol)

)

)) )

Question)22))

4)out)of)4)points)

) )

)

Measures)of)absolute,)attributable,)and)relative)risks)are)less)frequently)encountered)in)the)

clinical)literature)than)are)measures)of)population)risk.))

Answer)))) )



)

)) )

Question)23))

0)out)of)4)points)

) )

)

If)a)risk)factor)is)also)a)cause)of)disease,)removing)it)can)prevent)disease)whether)or)not)the)

mechanism)by)which)the)disease)develops)is)known.))) )



Answer))



)

)) )

Question)24))

4)out)of)4)points)

) )

)

Cohort)study)allows)for)accurate)measurement)of)disease)variables))

Answer)) )) )


False)


False)

)

)) )

Question)25))

4)out)of)4)points)

) )

)

))

The)incidence)of)disease)A)among)smokers)is)6/10000)and)is)(5)/)10000)among)nonsmokers.)

The)relative)risk)for)smoking=))

Answer))

)) )


1.2))


1.2))

)

)) )

Question)26))

4)out)of)4)points)

) )



)

)Exposure) ))))))))))))))))Outcome) )Total)

Yes) No)

Yes) 80) 20) 100)

No) 50) 50) 100)

Total) 130) 70) 200)

Relative)Risk=)

Answer))

)) )


1.6)


1.6)

)

)) )

Question)27))

4)out)of)4)points)

) )

)


572)per)100)000)in)nonsmokers,)and)892)per)100)000)in)smokers.))For)lung)cancer)the)figures)were)14)and)209,)respectively.)So,)a)comparatively)small)increase)in)risk)of)CHD,)associated)with)

smoking,)results)in)a)large)number)of)deaths.)))

Answer))

)) )



)

)) )

Question)28))

4)out)of)4)points)

) )

)

The)design)where)exposure)status)and)disease)status)are)measured)at)one)point)in)time)or)over)

a)period)is))

Answer)))) )




crosssectional))


crosssectional))

)

)) )

Question)29))

4)out)of)4)points)

) )

)

All)of)the)following)statements)are)true)about)both)prospective)and)retrospective)cohort)

studies)except:)

Answer)))) )


They)allow)investigators)to)decide)beforehand)what)data)to)collect)


They)allow)investigators)to)decide)beforehand)what)data)to)collect)

)

)) )

Question)30))

0)out)of)4)points)

) )

)



were)14)and)209,)respectively.)The)attributable)risk)of)lung)related)to)smoking)

Answer))

)) )

Selected)Answer:) )))[None)Given]))

Correct)Answer:) )f.)))

195))per)100)000)

)

)) )

Sunday,)February)24,)2013)10:16:04)AM)EST)

OK))



)



Score 84 out of 120 points

Time Elapsed 44 minutes out of 45 minutes.

Instructions

• Question 1

0 out of 4 points

The more sensitive a test is, the higher will be its false negative rate

Answer



• Question 2

4 out of 4 points

Diagnostic tests that discriminat well crowd toward the --------------------- of the ROC curve

Answer

Selected Answer:a.

upper left corner

Correct Answer:a.

upper left corner

• Question 3

0 out of 4 points

Posttest Odds =

Answer

Selected Answer:a.

Posttest Odds x Likelihood ratio

Correct Answer:b.

Pretest Odds x Likelihood ratio

• Question 4

0 out of 4 points



A test with 80% sensitivity and 90% specificity was applied to a populationwith 20% prevalence of a particular disease. The positive negative value was

94%. If the test is applied to another a population with 30% prevalence, thespecificity will be

Answer

Selected Answer:d.

95%

Correct Answer:c.

90%

• Question 5

4 out of 4 points

ROC curve is constructed by plotting

Answer

Selected Answer:c.

true positive rate against false-positive rate

Correct Answer:c.


• Question 6

4 out of 4 points

The probability that a patient has the disease given a positive test result.Answer

Selected Answer:c.

p(D+|T+)

Correct Answer:c.

p(D+|T+)

• Question 7

4 out of 4 points

The results of clinical tests are usually used not to categorically make or

exclude a diagnosis but to modify the pre-test probability in order to generate



the post-test probability.

Answer


Correct Answer:True

• Question 8

4 out of 4 points

If the posttest odds equals 4, then the posttest probability will beAnswer

Selected Answer:e.

80%

Correct Answer:e.

80%

• Question 9

4 out of 4 points

New Test

Gold Standard

Total

Disease No disease

Positive 90 30 120

Negative 10 70 80

Total 100 100 200

The prevalence of the disease is

Answer

Selected Answer:c.

50%

Correct Answer:c.



50%

• Question 10

4 out of 4 points

In a particular diagnostic testing the true positives or false negatives were 10and the true negatives or false positives were 20. The positive predictive

value of the test =Answer

Selected Answer:b.

33%

Correct Answer:b.

33%

• Question 11

4 out of 4 points

The more sensitive a test is, the lower will be its specificity

Answer

Selected Answer:

TrueCorrect Answer:

True

• Question 12

4 out of 4 points

Two tests are used in parallel with 60 and 80% sensitivities. If the two tests were completely

independent of each other then the sensitivity of parallel testing would be

Answer

Selected Answer: d.92%

Correct Answer:d.

92%

• Question 13



0 out of 4 points

All the following about sensitivity are true except

Answer

Selected

Answer:c.

A highly sensitive test is most helpful to the clinician when the test result

is negative

Correct

Answer:d.

A highly sensitive test is most helpful to the clinician when the test result

is positive

• Question 14

4 out of 4 points

Likelihood ratio is clinically more useful than sensitivity or specificity.

Answer


Correct Answer:True

• Question 15

4 out of 4 points

The likelihood ratio for a particular value of a diagnostic test is defined as the

Answer

Selected

Answer:b.

probability of that test result in people with the disease divided by the

probability of the result in people without disease

Correct

Answer:b.



• Question 16

0 out of 4 points

A new diagnostic test was applied to 200 subjects (50% healthy). The test was positive for 95

subjects of whom five were healthy by the gold standard. The positive predictive value is



Answer

Selected Answer:c.

50%

Correct Answer:a.

94.7%

• Question 17

4 out of 4 points

All the following about specificity are true except

Answer

SelectedAnswer:

a.

Specific tests are useful to rule out a diagnosis that has been suggested by

other data

Correct

Answer:a.


other data

• Question 18

0 out of 4 points


subjects of whom five were healthy by the gold standard. The negative predictive value is

Answer

Selected Answer:d.

50%

Correct Answer:c.

90.5%

• Question 19

4 out of 4 points

The sensitivity of Test A is 0.80 , and the specificity is 0.9. The LR + of this test



is

Answer

Selected Answer:d.

8

Correct Answer:d.

8

• Question 20

4 out of 4 points

It is desirable to have a test with

Answer

Selected Answer: c.

high sensitivity & high specificity

Correct Answer:c.


• Question 21

4 out of 4 points

Serial testing maximizes Answer

Selected Answer:f.

b and c

Correct Answer:f.

b and c

• Question 22

4 out of 4 points

The probability that a test result will be negative among patients without the

disease . Answer

Selected Answer:a.



p(T-|D - )

Correct Answer:a.

p(T-|D - )

• Question 23

0 out of 4 points

The prevalence of the disease has an impact on

Answer

Selected Answer:b.

sensitivity and positive predictive value

Correct Answer:d.

positive predictive value and negative predictive value

• Question 24

0 out of 4 points

The probability of event divided by the probability of no event is called

Answer

Selected Answer:a.

likelihood ratio

Correct Answer:c.

odds

• Question 25

4 out of 4 points

Disease is less likely in the presence of an extremely abnormal test result than it is for a

marginal one

Answer

Selected Answer:b.

false

Correct Answer:b.

false



• Question 26

4 out of 4 points

A psychiatrist devised a short screening test for depression. An independent blind comparison

was made with a gold standard for diagnosis of depression among 200 psychiatric outpatients.Among the 50 outpatients found to be depressed according to the gold standard, 35 patients

were positive for the test. Among 150 patients found not to be depressed according to the gold

standard, 30 patients were found to be positive for the test. Corrected to the nearest decimal

place:

Answer

Selected Answer:d.

The negative predictive value was 88.9%

Correct Answer:d.


• Question 27

4 out of 4 points

New Test

Gold Standard

Total

Disease No disease

Positive 90 30 120

Negative 10 70 80

Total 100 100 200

The specificity of the new test is

Answer

Selected Answer:d.

70%

Correct Answer:d.

70%

• Question 28

4 out of 4 points

Posttest odds=

Answer



Selected Answer:

pretest odds x LR

Correct Answer:

pretest odds x LR

• Question 29

0 out of 4 points

Multiple tests in parallel generally

Answer

Selected Answer:b.

increase the specificity and positive predictive value

Correct Answer: a.

increase the sensitivity and negative predictive value

• Question 30

4 out of 4 points

Specific tests are useful to rule out a diagnosis that has beensuggested by other data

Answer



• Question 1

4 out of 4 points

The results of clinical tests are usually used not to categorically make or exclude a diagnosis but to modify the pre-test probability in order to generate

the post-test probability.

Answer


Correct Answer:True

• Question 2



4 out of 4 points


subjects of whom five were healthy by the gold standard. The positive predictive value is

Answer

Selected Answer:a.

94.7%

Correct Answer:a.

94.7%

• Question 3

4 out of 4 points

The sensitivity and specificity of a test cannot be used to estimate probabilityof disease in individual patients.

Answer



• Question 4

0 out of 4 points

A test's negative likelihood ratio is calculated when the test result is negative

Answer

Selected Answer:b.

false

Correct Answer:a.

true

• Question 5

4 out of 4 points

Posttest Odds =

Answer



Selected Answer:b.


Correct Answer:b.


• Question 6

0 out of 4 points


subjects of whom five were healthy by the gold standard. The Prevalence of the disease is

Answer

Selected Answer:d.

90.5%

Correct Answer:e.

50%

• Question 7

4 out of 4 points

The probability that a patient does not have the disease given a negative testresult. Answer

Selected Answer:e.

p(D - |T - )

Correct Answer:e.

p(D - |T - )

• Question 8

0 out of 4 points


subjects of whom five were healthy by the gold standard. The sensitivity is



Answer

Selected Answer:b.

95%

Correct Answer:e.

90%

• Question 9

0 out of 4 points

Compared to whites of Norwegian descent, a test for sickle cell among AfricanAmerican would have higher Answer

Selected Answer:b.

specificity

Correct Answer:a.

positive predictive value

• Question 10

4 out of 4 points

A false negative results when a test indicates a positive status whenthe true status is negative

Answer



• Question 11

0 out of 4 points

The physician's estimate of the patient's likelihood of having the disease beforea diagnostic test is performed.Answer

Selected Answer:c.

pretest odds



Correct Answer:d.

a and b

• Question 12

4 out of 4 points

Serial testing maximizes

Answer

Selected Answer:f.

b and c

Correct Answer:f.

b and c

• Question 13

4 out of 4 points


Answer

Selected Answer:d.


Correct Answer: d.


• Question 14

4 out of 4 points

New Test

Gold Standard

Total Disease No disease

Positive 90 30 120 Negative 10 70 80

Total 100 100 200

LR+ =

Answer



Selected Answer:d.

90/30

Correct Answer:d.

90/30

• Question 15

4 out of 4 points

All the followings are false except

Answer

Selected

Answer:c.

The more sensitive a test is, the better will be its negative predictive

value

Correct Answer:c.

The more sensitive a test is, the better will be its negative predictive

value

• Question 16

4 out of 4 points

New Test

Gold Standard

Total

Disease No disease

Positive 90 30 120

Negative 10 70 80

Total 100 100 200

The prevalence of the disease is

Answer

Selected Answer:a.

50%



Correct Answer:a.

50%

• Question 17

4 out of 4 points

It is desirable to have a test with

Answer

Selected Answer:c.


Correct Answer:c.


• Question 18

4 out of 4 points

New Test

Gold Standard

Total

Disease No disease

Positive 90 30 120

Negative 10 70 80

Total 100 100 200

The specificity of the new test is

Answer

Selected Answer:a.

70%

Correct Answer:a.

70%

• Question 19

4 out of 4 points

In a particular diagnostic testing the true positives or false negatives were 10and the true negatives or false positives were 20. The positive predictive

value of the test =



Answer

Selected Answer:c.

33%

Correct Answer: c.

33%

• Question 20

0 out of 4 points

The probability that a test result will be positive among patients with thedisease.

Answer

Selected Answer:c.

p(T+|D+)

Correct Answer:d.

p(T+|D+)

• Question 21

0 out of 4 points

The likelihood ratio for a particular test is 4 and the pretest probability of thedisease is 20%. The posttest odds=Answer

Selected Answer:e.

0.25

Correct Answer:c.

1

• Question 22

4 out of 4 points

A test with 80% sensitivity and 90% specificity was applied to a population

with 20% prevalence of a particular disease. The positive negative value was94%. If the test is applied to another a population with 30% prevalence, the



specificity will be

Answer

Selected Answer:e.

90%

Correct Answer: e.

90%

• Question 23

4 out of 4 points

The probability that a test result will be negative among patients without the

disease . Answer

Selected Answer:c.

p(T-|D - )

Correct Answer:c.

p(T-|D - )

• Question 24

0 out of 4 points

In a particular diagnostic testing the true positives or false negatives were 10and the true negatives or false positives were 20. The negative predictivevalue of the test =Answer

Selected Answer:b.

67%

Correct Answer:d.

33%

• Question 25

0 out of 4 points

The area under the ROC curve (AUC) is calculated for five selected diagnostic tests as

follows: A(.6), B(.72), C(.82), D(.79), E(.87). Based on AUC, the best test is

Answer



Selected Answer:c.

C

Correct Answer:e.

E

• Question 26

0 out of 4 points


was made with a gold standard for diagnosis of depression among 200 psychiatric outpatients.

Among the 50 outpatients found to be depressed according to the gold standard, 35 patients



place:

Answer

Selected Answer:b.

The specificity was 88.9%

Correct Answer:d.


• Question 27

4 out of 4 points

New Test

Gold Standard

Total

Disease No disease

Positive 90 30 120

Negative 10 70 80

Total 100 100 200

The positive predictive value of the test is

Answer



Selected Answer:b.

75%

Correct Answer:b.

75%

• Question 28

4 out of 4 points


Answer

Selected

Answer:b.



Correct

Answer:b.



• Question 29

4 out of 4 points

In a particular diagnostic testing the true positives or false negatives were 10

and the true negatives or false positives were 20. The sensitivity of the test =Answer

Selected Answer:d.

50%

Correct Answer:d.

50%

• Question 30

4 out of 4 points

The probability of event divided by the probability of no event is called

Answer

Selected Answer:c.

odds



Correct Answer:c.

odds

Sunday, February 3, 2013 5:25:38 PM EST

• Question 1

4 out of 4 points


was made with a gold standard for diagnosis of depression among 200 psychiatric outpatients.

Among the 50 outpatients found to be depressed according to the gold standard, 35 patients



place:

Answer

Selected Answer:d.


Correct Answer:d.


• Question 2

4 out of 4 points

The likelihood ratio for a particular test is 4 and the pretest probability of thedisease is 20%. The posttest odds=Answer

Selected Answer:d.

1

Correct Answer:d.

1

• Question 3

4 out of 4 points

If the posttest odds equals 4, then the posttest probability will beAnswer

Selected Answer:e.



80%

Correct Answer:e.

80%

• Question 4

4 out of 4 points

A test with 80% sensitivity and 90% specificity was applied to a population

with 20% prevalence of a particular disease. The positive negative value was94%. If the test is applied to another a population with 30% prevalence, the

specificity will be

Answer

Selected Answer:e.

90%

Correct Answer:e.

90%

• Question 5

4 out of 4 points

The more sensitive a test is, the higher will be its false negative rate

Answer



• Question 6

0 out of 4 points

Gold Standard

Disease No disease



New Test Total

Positive 90 30 120

Negative 10 70 80

Total 100 100 200

The false positive rate =

Answer

Selected Answer:a.

90%

Correct Answer:b.

30%

•Question 7

0 out of 4 points

To evaluate the performance of a new diagnostic test, the developer checks it out on 100

known cases of the disease for which the test was designed, and on 200 controls known to be

free of the disease. Ninety of the cases yield positive tests, as do 30 of the controls. Based on

these data, the specificity and false positive error rates of the test are, respectively,

Answer

Selected Answer:a.

75% and 10%

Correct Answer:c.

85% and 15%

• Question 8

4 out of 4 points

Specific tests are useful to rule out a diagnosis that has beensuggested by other data

Answer



• Question 9

4 out of 4 points



Serial testing maximizes

Answer

Selected Answer:f.

b and c

Correct Answer:f.

b and c

• Question 10

4 out of 4 points

The sensitivity of Test A is 0.80 , and the specificity is 0.9. The LR + of this test

is

Answer

Selected Answer:d.

8

Correct Answer:d.

8

• Question 11

0 out of 4 points

A highly sensitive test is most helpful to the clinician when the test

result is positive

Answer



• Question 12

4 out of 4 points

New Test

Gold Standard

Total

Disease No disease

Positive 90 30 120

Negative 10 70 80



Total 100 100 200

The sensitivity of the test is

Answer

Selected Answer:d.

90%

Correct Answer:d.

90%

• Question 13

4 out of 4 points

If the pretest probability equals 60%, then the pretest odds will beAnswer

Selected Answer:b.

1.5

Correct Answer:b.

1.5

• Question 14

4 out of 4 points


subjects of whom five were healthy by the gold standard. The specificity is

Answer

Selected Answer:a.

95%

Correct Answer:a.

95%

• Question 15

0 out of 4 points




subjects of whom five were healthy by the gold standard. The sensitivity is

Answer

Selected Answer:b.

95%

Correct Answer:e.

90%

• Question 16

4 out of 4 points

Multiple tests in parallel generally increase the sensitivity and negative predictive value

Answer


Correct Answer:True

• Question 17

0 out of 4 points

A clinician uses the combination of multiple tests to arrive at a diagnosis. The results of the

combined testing from history, physical examination, and laboratory tests are used to make a

diagnosis. The resulting test combinations are called

Answer

Selected Answer:c.

receiver operator characteristic curve

Correct Answer:a.

clinical prediction rules

•Question 18

0 out of 4 points

In a particular diagnostic testing the true positives or false negatives were 10and the true negatives or false positives were 20. The likelihood ratio of the

test =Answer



Selected Answer:b.

2

Correct Answer:a.

1

• Question 19

4 out of 4 points

ROC curve is constructed by plotting

Answer

Selected Answer:c.


Correct Answer: c.


• Question 20

4 out of 4 points

The sensitivity and specificity of a test cannot be used to estimate probability

of disease in individual patients.

Answer



• Question 21

0 out of 4 points

When multiple tests are used, the accuracy of the final result depends on whether the

additional information contributed by each test is dependent on that already available from thepreceding ones.

Answer



• Question 22



4 out of 4 points

In a particular diagnostic testing the true positives or false negatives were 10

and the true negatives or false positives were 20. The negative predictivevalue of the test =

Answer

Selected Answer:e.

33%

Correct Answer:e.

33%

• Question 23

4 out of 4 points

All the following points about the ROC curve are true except

Answer

Selected

Answer:e.

The closer the curve follows the left-hand border and then the top border of

the ROC space, the less accurate the test

Correct

Answer:e.

The closer the curve follows the left-hand border and then the top border of

the ROC space, the less accurate the test

• Question 24

4 out of 4 points

The more sensitive a test is, the lower will be its specificity

Answer


Correct Answer:True

• Question 25

4 out of 4 points


Answer



Selected

Answer:b.



Correct

Answer:b.

probability of that test result in people with the disease divided by theprobability of the result in people without disease

• Question 26

4 out of 4 points

All the following about specificity are true except

Answer

Selected

Answer:

a.

Specific tests are useful to rule out a diagnosis that has been suggested byother data

Correct

Answer:a.


other data

• Question 27

4 out of 4 points


Answer

Selected Answer:d.


Correct Answer:d.


• Question 28

0 out of 4 points

The more specific a test is, the better will be its negative predictivevalue

Answer





• Question 29

4 out of 4 points

Posttest Odds =

Answer

Selected Answer:b.


Correct Answer:b.


•Question 30

4 out of 4 points

Likelihood ratio is clinically more useful than sensitivity or specificity.

Answer


Correct Answer:True

!



• Question 1

4 out of 4 points

If treatment B results in a 1% mortality and the placebo control group

has a mortality of 2%, then the relative improvement in mortality is Answer

Selected Answer:B.

50%

Correct Answer:B.

50%

• Question 2

4 out of 4 points

A mean difference between groups that is higher than the MID can be

considered asAnswer

Selected Answer:d.

clinically relevant

Correct Answer:d.

clinically relevant

• Question 3

4 out of 4 points

Effect size as a measure of clinical relevance can be used inAnswer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 4

4 out of 4 points



The smallest difference in score in the domain of interest that patients perceiveas important, either beneficial or harmful, and which would lead the clinician

to consider a change in the patient’s management Answer

Selected Answer:d.

Minimal important difference

Correct Answer:d.

Minimal important difference

• Question 5

4 out of 4 points

Absolute risk and relative risk are used as a proxy for

Answer

Selected Answer:b.

clinical significance

Correct Answer:b.


• Question 6

4 out of 4 points

Clinical significance is defined as

Answer

Selected Answer:c.

the practical value of a treatment effect

Correct Answer:c.

the practical value of a treatment effect

• Question 7

0 out of 4 points

Even though the difference between groups is small to be considered clinically

important, a statistical difference between groups could be found if Answer



Selected Answer:d.

all of the above

Correct Answer:e.

a and b

• Question 8

0 out of 4 points

Evidence-Based Medicine is a ‘cookbook medicine’ and is another way of

implementing treatment guidelines. Answer



• Question 9

4 out of 4 points

Determining success or failure of a treatment or preventive agent depends on

Answer

Selected Answer:e.

all of the above

Correct Answer:e.

all of the above

• Question 10

0 out of 4 points

A challenging issue in clinical research arises when

Answer

Selected

Answer:d.

statistically significant results are small and clinically not relevant

Correct Answer:b.

statistically non-significant results are large enough to be clinically

relevant



• Question 11

0 out of 4 points

Example of Anchor-based methods in the assessment of clinical relevance

Answer

Selected Answer:d.

clients’ perspective

Correct Answer:c.

calculation of the effect size

• Question 12

4 out of 4 points

The rates of remission of a major depressive episode at 6 weeks for drug A anddrug B were 29.5% and 31.5%. Therefore, the number needed to treat is

Answer

Selected Answer:a.

50

Correct Answer:a.

50

• Question 13

4 out of 4 points

If a p value > 0.05 is found, investigators must conclude that “there is sufficient evidence to

reject the null hypothesis".

Answer



• Question 14



4 out of 4 points

Large studies may show statistically significant findings that are not clinically significant

Answer

Selected Answer:a.

true

Correct Answer:a.

true

• Question 15

0 out of 4 points

In Bayesian interpretation, a 95% CI indicates that if the same study was

repeated many times, 95% of CI would include the true treatment effect.

Answer



• Question 16

4 out of 4 points

In the setting of a relatively safe treatment with no alternative treatment

options, the seriousness of type I error is relatively small, whereas the

seriousness of type II error is relatively large.

Answer


Correct Answer:True

• Question 17

4 out of 4 points

Positive conclusions should be based on

Answer

Selected Answer:c.

both a & b



Correct Answer:c.

both a & b

• Question 18

0 out of 4 points

The level of acceptable error (β error) usually is set at Answer

Selected Answer:A.

5%

Correct Answer:D.

20%

• Question 19

4 out of 4 points

Small studies may show clinically important findings that are not statistically significant

Answer

Selected Answer:a.

true

Correct Answer:

a.true

• Question 20

4 out of 4 points

If treatment A is associated with a 25% mortality and the placebocontrol group has a mortality of 50%, then the relative improvement inmortality is

Answer

Selected Answer:A.

50%

Correct Answer:A.

50%



• Question 21

4 out of 4 points

The magnitude of the effect size has been interpreted as an index of

Answer

Selected Answer:e.

clinical relevance

Correct Answer:e.

clinical relevance

• Question 22

4 out of 4 points

It is possible to haveAnswer

Selected Answer:e.

all of the above

Correct Answer:e.

all of the above

• Question 23

4 out of 4 points

A simplified but common interpretation of the p-value is that it is the probability that

Answer

Selected Answer:a.

the null hypothesis is true

Correct Answer:a.

the null hypothesis is true

• Question 24

0 out of 4 points

p value depends on

Answer



Selected Answer:e.

a & c only

Correct Answer:d.

all of the above

• Question 25

4 out of 4 points

Authors of RCTs usually report statistically significant differences between groups, and

conclusions are often based on this statistical significance. If P < 0.05, the conclusion is

usually that the intervention is

Answer

Selected Answer:d.

more effective than the comparison

Correct Answer:d.

more effective than the comparison

• Question 26

4 out of 4 points

The choice of the correct statistical test depends on

Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 27

4 out of 4 points

The degree to which the phenomenon is present in the population is defined as

Answer

Selected Answer:a.

Effect size

Correct Answer:a.



Effect size

• Question 28

4 out of 4 points

The definition of clinical significance depends on the

Answer

Selected Answer:e.

all of the above

Correct Answer:e.

all of the above

• Question 29

4 out of 4 points

Clinical relevance (also called clinical significance) assessment indicateswhether the results are meaningful or not. Answer


Correct Answer:True

• Question 30

4 out of 4 points

The number needed to treat (NNT) is used as a proxy for

Answer

Selected Answer:a.


Correct Answer:a.


• Question 1

4 out of 4 points

The choice of the correct statistical test depends on



Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 2

4 out of 4 points

Determining success or failure of a treatment or preventive agent depends on

Answer

Selected Answer:e.

all of the above

Correct Answer:e.

all of the above

• Question 3

4 out of 4 points

All the followings are true except

Answer

SelectedAnswer:

b.

Results of large studies are subject to more random error in comparison to

small studies

Correct

Answer:b.

Results of large studies are subject to more random error in comparison to

small studies

• Question 4

4 out of 4 points

Absolute risk and relative risk are used as a proxy for

Answer

Selected Answer:b.




Correct Answer:b.


• Question 5

0 out of 4 points

When we see p < 0.05 in a paper what is it telling us?

Answer

Selected

Answer:b.

The probability that this result is false is less than 5%.

Correct

Answer:d.

If there truly was no effect then one would expect to see a

result like this less than 5% of the time.

• Question 6

4 out of 4 points

If treatment A is associated with a 25% mortality and the placebocontrol group has a mortality of 50%, then the relative improvement inmortality is

Answer

Selected Answer: A.

50%

Correct Answer:A.

50%

• Question 7

4 out of 4 points

The level of acceptable error (β error) usually is set at

Answer

Selected Answer:D.

20%

Correct Answer:D.

20%



• Question 8

4 out of 4 points

All the following are examples of distribution-based methods to evaluate

clinical relevance exceptAnswer

Selected Answer:c.


Correct Answer:c.


• Question 9

4 out of 4 points

Findings that are novel or have clinical values are referred to in the biomedical literature as

Answer

Selected Answer:e.

all of the above

Correct Answer:e.

all of the above

• Question 10

4 out of 4 points

The probability of finding a statistically significant difference between

treatment groups in which the actual difference in means is at least as large asthe predetermined clinically relevant effect size. Answer

Selected Answer:C.

power

Correct Answer:C.

power

• Question 11

4 out of 4 points



The smaller the effect size, “the lower the degree to which the phenomenonunder study is manifested”. Answer



• Question 12

4 out of 4 points

The P value indicates if the effect is clinically important

Answer

Selected Answer:a.

false

Correct Answer:a.

false

• Question 13

4 out of 4 points

A meta-analysis may resolve the problem of underpowered studies. If findings are statistically

significant but not clinically important, ameta-analysis will change the conclusions.

Answer

Selected Answer:b.

false

Correct Answer:b.

false

• Question 14

0 out of 4 points

The P value is not very informative and only indicates the chance of the observed effect, not

considering its size

Answer

Selected Answer:a.

false

Correct Answer:b.



true

• Question 15

4 out of 4 points

If a p value > 0.05 is found, investigators must conclude that “there is sufficient evidence to

reject the null hypothesis".

Answer



• Question 16

4 out of 4 points

If treatment B results in a 1% mortality and the placebo control grouphas a mortality of 2%, then the relative improvement in mortality is Answer

Selected Answer:B.

50%

Correct Answer:B.

50%

• Question 17

4 out of 4 points

A confidence interval gives an estimated range of values for the variable of interest

Answer

Selected Answer:a.

true

Correct Answer:a.

true

• Question 18

4 out of 4 points



A p value is the probability that one would observe an effect (test statistic) as

extreme or more extreme than the one observed if the null hypothesis were

true.

Answer


Correct Answer:True

• Question 19

4 out of 4 points

It is possible to haveAnswer

Selected Answer: e.

all of the above

Correct Answer:e.

all of the above

• Question 20

4 out of 4 points

NNT is completely dependent on the statistical significance or the ‘P-value’. Answer



• Question 21

4 out of 4 points

Positive conclusions should be based on

Answer

Selected Answer:c.

both a & b

Correct Answer:c.

both a & b



• Question 22

4 out of 4 points

The number needed to treat (NNT) is used as a proxy for

Answer

Selected Answer:a.


Correct Answer:a.


• Question 23

4 out of 4 points

Example of Anchor-based methods in the assessment of clinical relevanceAnswer

Selected Answer:b.


Correct Answer:b.


• Question 24

4 out of 4 points

Information regarding the magnitude of association between variables as wellas the size of the difference between groups can be obtained using

Answer

Selected Answer:e.

Effect size

Correct Answer:e.

Effect size

• Question 25

4 out of 4 points

The 95% CI of an estimate is



Answer

Selected

Answer:c.

the range within which we are 95% certain that the true population

parameter will lie

CorrectAnswer:

c.the range within which we are 95% certain that the true population

parameter will lie

• Question 26

0 out of 4 points

If the NNT were 2, it would mean with every ---- patients a difference inoutcome would be seen. Answer

Selected Answer:c.

200

Correct Answer:e.

2

• Question 27

0 out of 4 points

Frequentist analysis allows for the inclusion of previous knowledge into study

analysis.

Answer



• Question 28

4 out of 4 points

The principles of significance and power are derived from the school of

statistical inference referred to as “ Bayesian statistics".

Answer





• Question 29

4 out of 4 points

Even though the difference between groups is small to be considered clinicallyimportant, a statistical difference between groups could be found if Answer

Selected Answer:e.

a and b

Correct Answer:e.

a and b

• Question 30

0 out of 4 points

The larger the effect size index, the smaller the difference between groups andthe larger the clinical relevance of the results. Answer



Saturday, January 26, 2013 11:43:00 PM EST

!



• Question 1

4 out of 4 points

The validity of a physical examination finding can be established by comparing it to the results of surgery or radiolo

examination.

Answer

Selected Answer:

TrueCorrect Answer:

True

• Question 2

0 out of 4 points

All the following data are termed "soft data" except

Answer

Selected Answer:b.

clinical performance data

Correct Answer:d.

demographic data

• Question 3

4 out of 4 points

Data that are measured on interval scales are often presented as

Answer

Selected Answer:c.

frequency distribution

Correct Answer:c.


• Question 4

4 out of 4 points

We assess construct validity by seeing whether a particular measure relates as it shouldother measures. Answer


Correct Answer:True

• Question 5



A patient is found to have a single serum cholesterol above 200 mg/dL, which is in the 65th percentile for adults in

United States and above a widely-accepted threshold for considering drug treatment. All of the followings are true e

Answer

Selected Answer:c.

The patient should be treated based on the observation that her cholesterol is higher than her p

Correct Answer:c.

The patient should be treated based on the observation that her cholesterol is higher than her p

• Question 6

4 out of 4 points

The degree to which a measurement truly measures what it purports to measure is

Answer

Selected Answer:b.

validity

Correct Answer:b.

validity

• Question 7

0 out of 4 points

The variability within subject is known as

Answer

Selected Answer:b.

analytical variability

Correct Answer:c.

biological variability

• Question 8

4 out of 4 points

The extent to which a measure appears to measure what it is supposed to measure Answer

Selected Answer:c.

face validity

Correct Answer:c.

face validity

• Question 9



0 out of 4 points

The New York Heart Association scale is not sensitive to subtle changes in congestive heart failure, one that matte

patients. Therefore, this scale has limited

Answer

Selected Answer:c.

interpretability

Correct Answer: b.

responsiveness

• Question 10

0 out of 4 points

The reliability of laboratory measurements is established by showing that they are similarly described to different

observers under different conditions.

Answer



• Question 11

0 out of 4 points

If a scale for measuring pain include questions about aching, throbbing, burning, and stinging but not about pressur

itching, nausea, and tingling, this scale would have

Answer

Selected Answer:b.

criterion validity

Correct Answer:d.

content validity

• Question 12

4 out of 4 points

In test-retest situations, regression to the mean refers to

Answer

Selected Answer:c.

both a and b

Correct Answer:c.

both a and b

• Question 13



4 out of 4 points

A scale based on questionnaire may have little intuitive meaning to clinicians and patients who do not use it regula

This scale has low

Answer

Selected Answer:a.

interpretability

Correct Answer: a.

interpretability

• Question 14

4 out of 4 points

Consider a dataset that contains the birthweight of all children born in Ohio during the last 50 years. Assuming that

dataset is normally distributed, which of the following statements is correct?

Answer

Selected Answer:a.

The mean, median, and mode share the same value

Correct Answer:a.


• Question 15

4 out of 4 points

Only random error is introduced by measurement variationAnswer



• Question 16

0 out of 4 points

The reliability of symptoms can be established by repeated measurement.

Answer



• Question 17

0 out of 4 points

All the followin s are methods for assessin reliabilit exce t



Answer

Selected Answer:b.

split-half

Correct Answer:d.

discriminant

• Question 18

4 out of 4 points

The extent to which a measure distinguishes participants on the basis of a particular behavioral criterion

Answer

Selected Answer:b.

criterion validity

Correct Answer:b.

criterion validity

• Question 19

0 out of 4 points

Conceptually, it is the average consistency across all possible split-half reliabilities. Answer

Selected Answer:a.

Significance level

Correct Answer:d.

Cronbach's alpha

• Question 20

0 out of 4 points

Ordinal scale is appropriate to use for

Answer

Selected Answer: d.All of the above

Correct Answer:e.

a and c only

• Question 21

4 out of 4 points



Sometimes extreme values are actually beneficial.

Answer


Correct Answer:True

• Question 22

4 out of 4 points

The reliability of any laboratory result is influenced by

Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 23

4 out of 4 points

Measures lacking face validity are not valid

Answer



• Question 24

4 out of 4 points

To separate normal from abnormal, we need to take into consideration

Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 25

0 out of 4 points

Observations that are close to the true are also

Answer

Selected Answer:b.



valid

Correct Answer:d.

all of the above

• Question 26

0 out of 4 points

Most biologic phenomena change from moment to moment.

Answer


Correct Answer:True

• Question 27

0 out of 4 points

If a scale measuring pain can predict mild pain from minor abrasion, moderate pain from ordinary headache, and se

pain from renal colic, this scale would have

Answer

Selected Answer:d.

content validity

Correct Answer:b.

criterion validity

• Question 28

4 out of 4 points

When it is not possible to verify measurement of a phenomenon, such as itching, by the physical senses, which of th

followings can be said of its validity?

Answer

Selected

Answer:c.

It can be supported by showing that the measurement is related to other measures of phenomena s

as the presence of diseases that are known to cause itching

CorrectAnswer:

c.

It can be supported by showing that the measurement is related to other measures of phenomena s

as the presence of diseases that are known to cause itching

• Question 29

0 out of 4 points



All the following are ordinal data except

Answer

Selected Answer:b.

recording of leg edema

Correct Answer:c.

demographics such as marital status

• Question 30

4 out of 4 points

Validity of a scale is either present or absent.

Answer



Sunday, January 20, 2013 5:30:59 PM EST

• Question 1

0 out of 4 points

All the following regarding criterion validity are true except:

Answer

Selected

Answer:[None Given]

Correct Answer:a.

ssed by seeing whether a particular measure relates as it should to other

measures.

• Question 2

0 out of 4 points

The Basic Activities of Daily Living scale that measure patients' ability in dressing, eating, walking, toileting and

maintaining hygiene does not measure ability to read, write, or do other activities that might be very important to

individual patients. Therefore, this scale has limitedAnswer


Correct Answer:a.

range

• Question 3



0 out of 4 points

A health practitioner encounters a dataset where diagnoses are coded with numbers. For example, pneumonia is coded

with a '1', hypertension is coded with a '2', appendicitis is coded with a '3', and so on. Which of the following best

describes the numerical component of this dataset?

Answer


Correct Answer: d.

Nominal Scale

• Question 4

0 out of 4 points

Face validity studies employ a reference standard (also called “gold standard”). Answer



• Question 5

0 out of 4 points

The validity of a physical examination finding can be established by comparing it to the results of surgery or radiologic

examination.

Answer

Selected Answer: [None Given]

Correct Answer:True

• Question 6

0 out of 4 points


Answer

SelectedAnswer: [None Given]

Correct

Answer:c.

Blood pressure measurements are related to risk of disease with threshold dividing normal from

increased risk.

• Question 7

0 out of 4 points



Measurement of ejection fraction by echocardiography can detect changes so subtle that patients do not notice them.

Therefore, this measure has high

Answer


Correct Answer:d.

responsiveness

• Question 8

0 out of 4 points

The followings are consequences of measurement error except

Answer


Correct Answer:c.

reduced significance level

• Question 9

0 out of 4 points

Criteria for abnormality

Answer


Correct Answer: d.all of the above

• Question 10

0 out of 4 points


Answer


Correct Answer:d.

all of the above

• Question 11

0 out of 4 points

All the followings are characteristics of medical measurements except

Answer




Correct Answer:a.

High validity (both internal and external)

• Question 12

0 out of 4 points

A statistical phenomenon that occurs when repeated measurements are made on the same subject or unit of observation.

Answer


Correct Answer:d.

Regression to the mean

• Question 13

0 out of 4 points

The variability within subject is known as

Answer


Correct Answer:c.

biological variability

• Question 14

0 out of 4 points


Answer



• Question 15

0 out of 4 points


Answer


Correct Answer:c.



both a and b

• Question 16

0 out of 4 points

Although clinical distributions often resemble a normal distribution the resemblance is superficial.

Answer


Correct Answer:True

• Question 17

0 out of 4 points

The extent to which a measure distinguishes participants on the basis of a particular behavioral criterion

Answer


Correct Answer:b.

criterion validity

• Question 18

0 out of 4 points

Systematic error, where the observed values are consistently biased, is not the cause of regression to the mean.Answer


Correct Answer:True

• Question 19

0 out of 4 points

"Abnormal" is commonly defined byAnswer


Correct Answer:e.

A and B only

• Question 20

0 out of 4 points



To have construct validity, a measure should

Answer

Selected Answers: [None Given]

Correct Answers:c.

both a and b

• Question 21

0 out of 4 points

The shape of clinical distributions differ from one another mainly because of random variations.

Answer



• Question 22

0 out of 4 points

A measure has face validity if Answer


Correct Answer:b.

people think it does

• Question 23

0 out of 4 points

All the followings are methods for assessing reliability except

Answer


Correct Answer:d.

discriminant

• Question 24

0 out of 4 points

The reliability of laboratory measurements is established by showing that they are similarly described to different

observers under different conditions.

Answer





• Question 25

0 out of 4 points


Answer


Correct Answer:d.

all of the above

• Question 26

0 out of 4 points


Answer


Correct Answer:e.

a and c only

• Question 27

0 out of 4 points

The extent to which a measure appears to measure what it is supposed to measure Answer


Correct Answer:c.

face validity

• Question 28

0 out of 4 points

As the prevalence of disease rises with age, the number of people with unidentified abnormalities is also likely to

decrease.

Answer




Correct Answer:b.

false

• Question 29

0 out of 4 points

Regression to the mean is not restricted to distributions that are Normal, or even to distributions that are continuous.

Answer


Correct Answer:True

• Question 30

0 out of 4 points

Consider a dataset that contains the birthweight of all children born in Ohio during the last 50 years. Assuming that thisdataset is normally distributed, which of the following statements is correct?

Answer


Correct Answer:a.


• Question 1

0 out of 4 points

All the following are nominal data except

Answer

Selected Answer:e.

Hospital location as rural or urban

Correct Answer:c.

Demographics such as socioeconomic status

• Question 2

4 out of 4 points

All the following are interval data except

Answer

Selected Answer:b.

risk of birth defect from drug during pregnancy



Correct Answer:b.

risk of birth defect from drug during pregnancy

• Question 3

4 out of 4 points

Blood pressure is generally higher when people are

Answer

Selected Answer:e.

a and b

Correct Answer:e.

a and b

• Question 4

4 out of 4 points


Answer



• Question 5

4 out of 4 points

Consider a dataset that contains the birthweight of all children born in Ohio during the last 50 years. Assuming that this

dataset is normally distributed, which of the following statements is correct?

Answer

Selected Answer:a.


Correct Answer:a.


• Question 6

4 out of 4 points


Answer

Selected Answer:e.

a and c only



Correct Answer:e.

a and c only

• Question 7

4 out of 4 points



individual patients. Therefore, this scale has limited

Answer

Selected Answer:a.

range

Correct Answer:a.

range

• Question 8

4 out of 4 points


Answer

Selected Answer:c.

both a and b

Correct Answer:c.

both a and b

• Question 9

4 out of 4 points


Answer



• Question 10

0 out of 4 points

Hemoglobin values follow a positively skewed distribution

Answer





• Question 11

4 out of 4 points

A randomized placebo controlled trial was carried out among subjects with mild hypertension. Among 1000 subjects

allocated to active treatment there were 10 strokes. Among 1000 subjects allocated to placebo there were 20 strokes.What is the number needed to treat (NNT) to prevent a single stroke under the conditions of this trial?

Answer

Selected Answer:e.

100

Correct Answer:e.

100

• Question 12

0 out of 4 points

Coefficient of Variation is basically the

Answer

Selected Answer:c.

standard deviation multiplied by the mean

Correct Answer:e.

standard deviation divided by the mean

• Question 13

4 out of 4 points

A population having a specific disease will usually have an asymmetric distribution. Answer


Correct Answer:True

• Question 14

4 out of 4 points

A physician or nurse measures a patient's heart rate by feeling the pulse for 10 seconds each time she comes to clinic. The

rates might differ from visit to visit because of all of the followings except:

Answer

Selected Answer:a.

The pulse rate varies among patients



Correct Answer:a.

The pulse rate varies among patients

• Question 15

4 out of 4 points


Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 16

4 out of 4 points

Just because a measure has face validity does not ensure that it is a valid measure Answer


Correct Answer:True

• Question 17

4 out of 4 points

Observations that are reproducible are also

Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 18

4 out of 4 points

Systematic error, where the observed values are consistently biased, is not the cause of regression to the mean.

Answer


Correct Answer:True



• Question 19

4 out of 4 points


Answer

Selected Answer:a.


Correct Answer:a.


• Question 20

4 out of 4 points

The degree to which a measurement provides the same result each time it is performed on a given subject or specimen is

Answer

Selected Answer:a.

reliability

Correct Answer:a.

reliability

• Question 21

4 out of 4 points


Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 22

0 out of 4 points

Regression to the mean happens because of a systematic variation in the observed values around a true mean.

Answer



• Question 23



4 out of 4 points


Answer


Correct Answer:True

• Question 24

4 out of 4 points

If a scale measuring pain can predict mild pain from minor abrasion, moderate pain from ordinary headache, and severe

pain from renal colic, this scale would have

Answer

Selected Answer:a.

criterion validity

Correct Answer: a.criterion validity

• Question 25

4 out of 4 points

The absolute value of the average difference of individual values from the mean is called

Answer

Selected Answer:d.

Standard deviation

Correct Answer:d.

Standard deviation

• Question 26

4 out of 4 points

Only random error is introduced by measurement variation

AnswerSelected Answer:

False


• Question 27

4 out of 4 points

Conceptually, it is the average consistency across all possible split-half reliabilities.



Answer

Selected Answer:d.

Cronbach's alpha

Correct Answer:d.

Cronbach's alpha

• Question 28

4 out of 4 points


Answer

Selected Answer:c.


Correct Answer:c.


• Question 29

4 out of 4 points

A patient is found to have a single serum cholesterol above 200 mg/dL, which is in the 65th percentile for adults in the

United States and above a widely-accepted threshold for considering drug treatment. All of the followings are true except

Answer

Selected Answer:c.

The patient should be treated based on the observation that her cholesterol is higher than her peers.

Correct Answer:c.

The patient should be treated based on the observation that her cholesterol is higher than her peers.

• Question 30

4 out of 4 points

The validity of a physical examination finding can be established by comparing it to the results of surgery or radiologic

examination.

Answer


Correct Answer:True

• Question 1

4 out of 4 points

Coefficient of Variation is basicall the



Answer

Selected Answer:e.


Correct Answer:e.


• Question 2

0 out of 4 points

All the followings are true except

Answer

Selected Answer:b.

The normal distribution is unimodal and symmetrical

Correct Answer:d.

The normal distribution is the best basis for defining abnormal

• Question 3

4 out of 4 points

One common way of establishing a cutoff point between normal and abnormal is to agree, somewhat arbitrarily, that all

values beyond ---- standard deviations from the mean are abnormal

Answer

Selected Answer:b.

2

Correct Answer:b.

2

• Question 4

4 out of 4 points


Answer

Selected Answer:a.


Correct Answer:a.


• Question 5

4 out of 4 points




Answer

Selected Answer:d.

discriminant

Correct Answer:d.

discriminant

• Question 6

0 out of 4 points


Answer



• Question 7

0 out of 4 points



Correct Answer:True

• Question 8

0 out of 4 points

Some clinical measurements such as pain, nausea, dyspnea, depression, and fear cannot be verified physically. In patient

care, information about these phenomena is usually obtained informally by

Answer

Selected Answer:e.

all of the above

Correct Answer: c.taking a history

• Question 9

4 out of 4 points


Answer



Selected Answer:a.


Correct Answer:a.


• Question 10

4 out of 4 points

All the following assertions about regression to the mean phenomenon are true except

Answer

Selected Answer:a.

The more extreme the initial reading is, the more likely it is to be normal when repeated

Correct Answer:a.

The more extreme the initial reading is, the more likely it is to be normal when repeated

• Question 11

4 out of 4 points

A scale based on questionnaire may have little intuitive meaning to clinicians and patients who do not use it regularly.

This scale has low

Answer

Selected Answer:a.

interpretability

Correct Answer:a.

interpretability

• Question 12

4 out of 4 points

As the prevalence of disease rises with age, the number of people with unidentified abnormalities is also likely to

decrease.

Answer

Selected Answer:b.

false

Correct Answer:b.

false

• Question 13

0 out of 4 points




Answer

Selected Answer:e.

a and b only

Correct Answer:d.

all of the above

• Question 14

4 out of 4 points


Answer

Selected Answer:c.


Correct Answer:c.


• Question 15

4 out of 4 points

Regression to the mean affects all fields of life science, when effects of an intervention have

to be evaluated in an uncontrolled longitudinal setting.

Answer


Correct Answer:True

• Question 16

0 out of 4 points




Answer

Selected Answer:a.

responsiveness

Correct Answer:b.

range

• Question 17

4 out of 4 oints



Whether the measurement is consistent with other measurements of the same phenomenon is known as

Answer

Selected Answer:a.

construct validity

Correct Answer:a.

construct validity

• Question 18

4 out of 4 points


Answer

Selected

Answer:e.


increased risk.

Correct

Answer:e.


increased risk.

• Question 19

4 out of 4 points

Observations that are thought to be normal are usually described as

Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 20

4 out of 4 points

The degree to which a measurement provides the same result each time it is performed on a given subject or specimen is

Answer

Selected Answer:a.

reliability

Correct Answer:a.

reliability

• Question 21



4 out of 4 points


Answer

Selected Answer:d.

all of the above

Correct Answer:

d.all of the above

• Question 22

4 out of 4 points


Answer

Selected Answer:c.


Correct Answer:c.


• Question 23

4 out of 4 points

The distribution of values for many laboratory tests changes with

Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 24

4 out of 4 points


Answer



• Question 25

4 out of 4 points



Regression towards the mean occurs whenever we select an extreme group based on one variable and then measure

another variable for that group.

Answer

Selected Answer:a.

true

Correct Answer:a.

true

• Question 26

0 out of 4 points

To compare different sets of observations relative to their means, you should use

Answer

Selected Answer:a.

standard deviation

Correct Answer:c.

coefficient of variation

• Question 27

4 out of 4 points


Answer

Selected Answer: c.

both a and b

Correct Answer:c.

both a and b

• Question 28

4 out of 4 points

The absolute value of the average difference of individual values from the mean is calledAnswer

Selected Answer:d.

Standard deviation

Correct Answer:d.

Standard deviation

• Question 29



4 out of 4 points

Regression to the mean happens because of a systematic variation in the observed values around a true mean.

Answer



• Question 30

4 out of 4 points


Answer



• Question 1

4 out of 4 points

To compare different sets of observations relative to their means, you should use

Answer

Selected Answer:c.


Correct Answer:c.


• Question 2

4 out of 4 points

Hemoglobin values follow a positively skewed distribution

Answer



• Question 3

4 out of 4 points


Answer





• Question 4

4 out of 4 points


Answer


Correct Answer:True

• Question 5

4 out of 4 points

The New York Heart Association scale is not sensitive to subtle changes in congestive heart failure, one that matter to

patients. Therefore, this scale has limitedAnswer

Selected Answer:b.

responsiveness

Correct Answer:b.

responsiveness

• Question 6

4 out of 4 points

Measurement of ejection fraction by echocardiography can detect changes so subtle that patients do not notice them.

Therefore, this measure has high

Answer

Selected Answer:d.

responsiveness

Correct Answer:d.

responsiveness

• Question 7

4 out of 4 points



Correct Answer:True



• Question 8

4 out of 4 points


Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 9

0 out of 4 points

A strong relationship exists beween the degree of statistical unusualness and clinical disease.

Answer



• Question 10

4 out of 4 points


Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 11

4 out of 4 points

Systematic error, where the observed values are consistently biased, is not the cause of regression to the mean.

Answer


Correct Answer:True

• Question 12

4 out of 4 points




Answer

Selected Answer:d.

discriminant

Correct Answer:d.

discriminant

• Question 13

0 out of 4 points

When comparing multiple markers for the same outcome, the marker with the lowest biological variation is most

beneficial

Answer

Selected Answer:b.

false

Correct Answer: a.

true

• Question 14

4 out of 4 points

We assess construct validity by seeing whether a particular measure relates as it should toother measures. Answer


Correct Answer:True

• Question 15

4 out of 4 points




Answer

Selected Answer:c.

range

Correct Answer:c.

range

• Question 16



4 out of 4 points


Answer

Selected Answer:c.


Correct Answer:

c.frequency distribution

• Question 17

4 out of 4 points


Answer

Selected Answer:a.


Correct Answer:a.


• Question 18

4 out of 4 points

Regression to the mean affects all fields of life science, when effects of an intervention have

to be evaluated in an uncontrolled longitudinal setting.

Answer


Correct Answer:True

• Question 19

4 out of 4 points

Conceptually, it is the average consistency across all possible split-half reliabilities. Answer

Selected Answer:d.

Cronbach's alpha

Correct Answer:d.

Cronbach's alpha

• Question 20



4 out of 4 points

Although clinical distributions often resemble a normal distribution the resemblance is superficial.

Answer


Correct Answer:True

• Question 21

4 out of 4 points


Answer

Selected Answer:c.


Correct Answer:c.


• Question 22

4 out of 4 points


Answer

Selected

Answer:d.


increased risk.

Correct

Answer:d.


increased risk.

• Question 23

4 out of 4 points

The distribution of values for many laboratory tests changes withAnswer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 24



4 out of 4 points


Answer

Selected Answer:a.


Correct Answer:

a.High validity (both internal and external)

• Question 25

4 out of 4 points

To have construct validity, a measure should

Answer

Selected Answers:c.

both a and b

Correct Answers:c.

both a and b

• Question 26

4 out of 4 points


Answer



• Question 27

4 out of 4 points

Overall variation is the sum of variation related to

Answer

Selected Answer:a.

all of the above

Correct Answer:a.

all of the above

• Question 28



0 out of 4 points

Most biologic measurements are normally distributed.

Answer



• Question 29

4 out of 4 points


Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 30

4 out of 4 points

Some clinical measurements such as pain, nausea, dyspnea, depression, and fear cannot be verified physically. In patient

care, information about these phenomena is usually obtained informally by

Answer

Selected Answer:c.

taking a history

Correct Answer:c.

taking a history

!



• Question 1

4 out of 4 points

The biggest threat to validity in a clinical trial comparing two types of treatment therapy is

Answer

Selected Answer:e.

selection bias

Correct Answer:e.

selection bias

• Question 2

0 out of 4 points

In contrast to random error, which diminishes as sample size increases, systematic error

Answer

Selected Answer:c.

increases as sample size increases

Correct Answer:a.

is independent of the size of the study population

• Question 3

4 out of 4 points

The degree to which the results of an observation hold true in other settings is

Answer

Selected Answer:d.

generalizability

Correct Answer:d.

generalizability

• Question 4

4 out of 4 points

All systematic errors can be controlled in the phase corresponding to analysis

of the results.



Answer



• Question 5

0 out of 4 points

Which of the following is true?

Answer

Selected Answer:b.

A study can be externally valid but not internally valid

Correct Answer:a.

A study can be internally valid but not externally valid

• Question 6

4 out of 4 points

When the magnitude of the bias is related to exposure to the study factor on the

part of the subject or the condition of his or her disease. Answer

Selected Answer:a.

Differential information bias

Correct Answer:a.


• Question 7

4 out of 4 points

The attribute of patients and clinical events are called

Answer

Selected Answer:a.

variables

Correct Answer:a.

variables



• Question 8

4 out of 4 points

All the following methods for controlling a confounding factor are applicable at the stage of

study design except:Answer

Selected Answer:c.

stratification

Correct Answer:c.

stratification

• Question 9

0 out of 4 points

A sophisticated statistical method available to adjust simultaneously for various confounding

factors

Answer

Selected Answer:d.

stratification

Correct Answer:b.

regression modelling

• Question 10

0 out of 4 points

A failure to secure the participation of all the selected sample units

Answer

Selected Answer:a.

Neyman bias

Correct Answer:

c. Non-response bias

• Question 11

0 out of 4 points



Random error Answer

Selected Answer:e.

Affects the accuracy of the measurements

Correct Answer: b.

Does not always occur in the same direction.

• Question 12

0 out of 4 points

The divergence of an observation on a sample from the true population value, due to chance

alone, is called

Answer

Selected Answer:a.

Systematic error

Correct Answer:b.

Random variation

• Question 13

0 out of 4 points

A confounding factor may or may not carry some causal relationship to theoutcome.

Answer

Selected Answer:B.

false

Correct Answer:A.

true

• Question 14

4 out of 4 points

A variable is confounded if it is directly along the path from cause to effect.



Answer



• Question 15

4 out of 4 points

Cronbach coefficient is used to assess

Answer

Selected Answer:c.

internal consistency

Correct Answer:c.

internal consistency

• Question 16

0 out of 4 points

All the following disorders or disabilities are associated with confounding by indication

except:

Answer

Selected Answer:c.

ADL

Correct Answer:d.

Vigorous exercise

• Question 17

0 out of 4 points

The effects of bias and chance are

Answer

Selected Answer:a.

Mutually exclusive

Correct Answer:c.

Cumulative



• Question 18

0 out of 4 points

The degree to which the results of a study are correct for the sample of patients being studied

is calledAnswer

Selected Answer:a.

test-retest reliability

Correct Answer:c.

internal validity

• Question 19

0 out of 4 points

There are sharp distinctions among the biologic sciences (such as anatomy and physiology).

Answer



• Question 20

0 out of 4 points

The clinical events of primary interest in clinical epidemiology are

Answer

Selected Answer:a.

signs, symptoms, and admissions

Correct Answer:c.

symptoms, disability, and death

• Question 21

4 out of 4 points

A bias arises from the fact that those who take medication generally differ from those who do

not under medical indication. These differences introduce a bias in the comparison.

Answer



Selected Answer:c.

Confounding by indication

Correct Answer:c.

Confounding by indication

• Question 22

0 out of 4 points

An investigation in which one group of allergic children receives a new drug

treatment and another receives the usual drug treatment. If the investigator isalso the observer, he or she will tend to be more meticulous in evaluating the

new drug treatment group than the other group, even if not deliberately so. Answer

Selected Answer:b.

confounding bias

Correct Answer:e.

none of the above

• Question 23

0 out of 4 points

The inclusion of a large number of subjects in a study

Answer

Selected Answer:d.

Reduces information bias

Correct Answer:a.

Allows precise risk estimates to be calculated

• Question 24

4 out of 4 points

Understanding the biology of disease is often not, in itself, a sound basis for prediction in

intact humans.

Answer




Correct Answer:True

• Question 25

4 out of 4 points

Clinical outcomes, such as occurrence of disease, death, symptoms, or disability, can be

counted and expressed as numbers.

Answer


Correct Answer:True

• Question 26

4 out of 4 points

Good decisions depend on

Answer

Selected Answer:d.

all of the above

Correct Answer:d.

all of the above

• Question 27

0 out of 4 points

Which of the following is/are true? I. Bias results from systematic flaws in study design II.

Bias results from systematic flaws in data collection III. Bias results from systematic flaws in

the analysis or interpretation of results

Answer

Selected Answer:b.

I and III only are true.

Correct Answer: a.

I, II, and III are all true.

• Question 28

4 out of 4 points



The gene for phenylketon uria is expressed only in children who ingest phenylalanine in their

diet.

Answer


Correct Answer:True

• Question 29

4 out of 4 points

Clinical epidemiology is the application of epidemiologic principles to problems encountered

in clinical medicine.

Answer

Selected Answer:a.

true

Correct Answer:a.

true

• Question 30

0 out of 4 points

Not all studies are generalizable to patients very much like the ones in the study.

Answer



• Question 1

4 out of 4 points

The$generalizability$of$clinical$observations,$even$those$with$high$internal$validity,$is$a$matter$of$personal$judgment$about$which$reasonable$people$

might$disagree.$Answer$

Selected$Answer:$ $True

Correct$Answer:$ $True

• Question 2



4 out of 4 points

Confounding bias is the only one of the three types of bias that can be

controlled both in the study design phase and posteriorly in the analytical phase of an epidemiological study.

Answer$



• Question 3

0 out of 4 points

Different drug classes have been recommended in the control of

hyperglycaemia and prevention of diabetes complications. To this end,diabetes is associated with multiple risk factors for complications and thus,subjects requiring drug treatment are often high risk individuals for

hypertension, CVD, renal disease and cancer. Thus, drug use indication bias isa systematic error due to$

Answer$

Selected$Answer: $$$$Confounding$

Correct$Answer: $$$$

Selection bias

• Question 4

0 out of 4 points

A$RCT$of$10,000$adults$was$conducted$to$determine$if$a$new$antiplatelet$

medication$taken$with$aspirin$is$better$than$aspirin$taken$alone$in$

subjects$with$heart$disease.$The$outcome$of$interest$was$MI$(heart$attack).$

Select$the$best$answer:$

Answer$

Selected$

Answer: $a.$$$

It$is$possible$that$confounding$by$the$new$antiplatelet$medication$could$occur.

Correct$ $b.$$$



Answer: It$is$possible$that$effect$modification$by$the$new$anti

platelet$medication$could$occur.

• Question 5

4 out of 4 points

In$contrast$to$random$error,$which$diminishes$as$sample$size$increases,$

systematic$error$$

Answer$

Selected$Answer: $b.$$$

is$independent$of$the$size$of$the$study$population$

Correct$Answer: $b.$$$

is$independent$of$the$size$of$the$study$population$

• Question 6

0 out of 4 points

All$the$followings$are$measurement$bias$except$

Answer$

Selected$Answer: $e.$$$

Incomplete$recording

Correct$Answer: $d.$$$

Selection$bias

• Question 7

0 out of 4 points

The presence of systematic error affects

Answer$ Selected$Answer: $a.$$$

internal validity of the study

Correct$Answer: $e.$$$only a and b



• Question 8

0 out of 4 points

Women with allergic children will remember better, or make a greater effort to

remember, their eating habits during pregnancy than women with healthychildren. This is an example of

Answer$


none of the above

Correct$Answer: $a.$$$ participant bias

• Question 9

0 out of 4 points

In case-control study, admission rate bias can be avoided by selecting the

controls from among people admitted to the hospital in the same period of time but due to other causes. Compared to cases, the probability of admission to

hospital for diseases included as controls must be

Answer$

Selected$Answer: $c.$$$

Lower

Correct$Answer: $d.$$$Similar

• Question 10

4 out of 4 points

All$the$following$disorders$or$disabilities$are$associated$with$confounding$

by$indication$except:$

Answer$

Selected$Answer: $d.$$$

Vigorous$exercise$


Vigorous$exercise$



• Question 11

0 out of 4 points

A$modern$term$for$the$application$of$clinical$epidemiology$to$the$care$of$

patients$is$$Answer$

Selected$Answers:$ $B.$$$

Evidencebased$medicine$$

$

$C.$$$

Clinical$medicine$$$

$

Correct$Answers: $B.$$$Evidencebased$medicine$$

$

$

• Question 12

4 out of 4 points

Systematic error can be classified as

Answer$

Selected$Answer: $d.$$$all of the above


all of the above

• Question 13

0 out of 4 points

Histamine$is$a$mediator$of$inflammation$in$patients$with$allergic$rhinitis.$Based$on$this$fact,$which$of$the$following$is$true?$

Answer$

Selected$

Answer: $a.$$$

Drugs$that$block$the$effects$of$histamines$will$relieve$

symptoms.



Correct$

Answer: $c.$$$

Antihistamines$may$be$effective$and$their$effects$on$

symptoms$(such$as$itching,$sneezing$and$congestion)$

should$be$studied$in$patients$with$allergic$rhinitis.

• Question 14

4 out of 4 points

The$effects$of$bias$and$chance$are$Answer$


Cumulative

Correct$Answer: $c.$$$Cumulative

• Question 15

4 out of 4 points

Understanding$the$biology$of$disease$is$often$not,$in$itself,$a$sound$basis$

for$prediction$in$intact$humans.$

Answer$



• Question 16

4 out of 4 points

An investigation in which one group of allergic children receives a new drugtreatment and another receives the usual drug treatment. If the investigator is

also the observer, he or she will tend to be more meticulous in evaluating thenew drug treatment group than the other group, even if not deliberately so.

Answer$

Selected$Answer: $e.$$$none of the above

Correct$Answer: $e.$$$



none of the above

• Question 17

4 out of 4 points

Observation$about$disease$are$ordinarily$made$on$a$sample$of$patients$

because$$

Answer$

Selected$Answer: $a.$$$

it is not possible to study all patients with the disease in question.

Correct$Answer: $a.$$$


• Question 18

0 out of 4 points

A$purported$cause$or$predictor$variable$is,$sometimes,$called$the$

dependent$variable.$Answer$


Correct$Answer:$ $False

• Question 19

4 out of 4 points

Which$of$the$following$is$true?$

Answer$

Selected$Answer:

$a.$$$A$study$can$be$internally$valid$but$not$externally$

valid


A$study$can$be$internally$valid$but$not$externally$

valid



• Question 20

0 out of 4 points

Quantitative$decision$analysis$include$$

Answer$


decision$analysis$


a$$and$c$

• Question 21

4 out of 4 points


Answer$


Non-response bias

Correct$Answer: $c.$$$ Non-response bias

• Question 22

4 out of 4 points

All$the$followings$are$true$except$

Answer$

Selected$

Answer: $a.$$$

Samples$of$populations$must$have$characteristics$that$are$

exactly$similar$to$the$parent$population$

Correct$Answer:

$a.$$$



• Question 23

4 out of 4 points



Bias occurs when the cases and/or controls are recruited from amonghospitalized patients.

Answer$


Berkson bias

Correct$Answer: $b.$$$Berkson bias

• Question 24

4 out of 4 points

A type of bias occurs when we study a disease that causes early death, and at

the start of the study the deceased individuals can no longer be included in thecase group.

Answer$


Neyman bias


Neyman bias

• Question 25

0 out of 4 points

A$bias$arises$from$the$fact$that$those$who$take$medication$generally$differ$

from$those$who$do$not$under$medical$indication.$These$differences$

introduce$a$bias$in$the$comparison.$$

Answer$


Medication$bias$

Correct$Answer: $e.$$$Confounding$by$indication$

• Question 26

4 out of 4 points



Not$all$studies$are$generalizable$to$patients$very$much$like$the$ones$in$the$

study.$

Answer$

Selected$Answer:$ $False


• Question 27

4 out of 4 points

Random$variation$tends$to$distort$the$clinical$observations$in$one$

direction$or$the$other.$$

Answer$



• Question 28

4 out of 4 points

The$inclusion$of$a$large$number$of$subjects$in$a$study$$Answer$


Allows$precise$risk$estimates$to$be$calculated$



• Question 29

4 out of 4 points

When the magnitude of the bias is related to exposure to the study factor on the

part of the subject or the condition of his or her disease.

Answer$







• Question 30

4 out of 4 points

Which$of$the$following$is/are$true?$I.$Bias$results$from$systematic$flaws$in$

study$design$II.$Bias$results$from$systematic$flaws$in$data$collection$III.$

Bias$results$from$systematic$flaws$in$the$analysis$or$interpretation$of$

results$

Answer$


I,$II,$and$III$are$all$true.

Correct$Answer: $a.$$$I,$II,$and$III$are$all$true.

Saturday, January 12, 2013 4:02:30 PM EST

• Question 1

4 out of 4 points

Bias occurs when the cases and/or controls are recruited from among

hospitalized patients. Answer$

Selected$Answer: $b.$$$Berkson bias


Berkson bias

• Question 2

4 out of 4 points

A confounding factor may or may not carry some causal relationship to the

outcome.

Answer$



Selected$Answer: $A.$$$

true

Correct$Answer: $A.$$$

true

• Question 3

4 out of 4 points

All$the$followings$are$measurement$bias$except$Answer$

Selected$Answer: $d.$$$Selection$bias


Selection$bias

• Question 4

4 out of 4 points

The$degree$to$which$the$results$of$an$observation$hold$true$in$other$settings$is$$

Answer$


generalizability

Correct$Answer: $d.$$$generalizability

• Question 5

4 out of 4 points

The$degree$to$which$the$results$of$a$study$are$correct$for$the$sample$of$

patients$being$studied$is$called$$

Answer$




internal$validity$

Correct$Answer: $c.$$$internal$validity$

• Question 6

4 out of 4 points

Good$decisions$depend$on$$

Answer$

Selected$Answer: $d.$$$all$of$the$above$


all$of$the$above$

• Question 7

4 out of 4 points


remember, their eating habits during pregnancy than women with healthy

children. This is an example of Answer$

Selected$Answer: $c.$$$Differential information bias

Correct$Answer: $c.$$$


• Question 8

4 out of 4 points

Random error

Answer$

Selected$Answer: $d.$$$Does not always occur in the same direction.$




Does not always occur in the same direction.$

• Question 9

4 out of 4 points

There$is$a$positive$association$between$carrying$matches$and$lung$cancer.$

This$is$an$example$of$an$association$likely$caused$by:$

Answer$


confounding$factor


confounding$factor

• Question 10

4 out of 4 points


Answer$


all of the above


all of the above

• Question 11

4 out of 4 points

In$a$randomized$controlled$trial,$the$following$type$of$bias$is$reduced$by$

randomization$$Answer$


Selection$bias$




Selection$bias$

• Question 12

4 out of 4 points



Answer$



• Question 13

4 out of 4 points

Select$the$best$statement$concerning$recall$bias:$

Answer$

Selected$

Answer: $d.$$$

It$occurs$when$cases$and$controls$know$their$outcome$

status$and$differentially$recall$their$exposure$history$in$a$

case$control$study.

Correct$Answer:

$d.$$$It$occurs$when$cases$and$controls$know$their$outcome$


case$control$study.

• Question 14

0 out of 4 points

In a population with a high incidence of cardiovascular disease, diabetics are at

least twice as likely to die from myocardial infarction as are non-diabetics. Acase-control study conducted in the community identifies 1,000 people with

sustained myocardial infarction and 1,000 people without sustained myocardialinfarction. The subjects are asked whether they have a history of diabetes

mellitus. According to the study results, diabetes has a protective effect againstmyocardial infarction. Which of the following best explains the observed study

results?$$

Answer$




Observer bias$

Correct$Answer: $c.$$$Selection bias$

• Question 15

4 out of 4 points

Women with allergic children will remember better, or make a greater effort toremember, their eating habits during pregnancy than women with healthy

children. This is an example of

Answer$

Selected$Answer: $a.$$$ participant bias

Correct$Answer: $a.$$$ participant bias

• Question 16

4 out of 4 points

All systematic errors can be controlled in the phase corresponding to analysisof the results.

Answer$



• Question 17

4 out of 4 points


Answer$

Selected$Answer: $e.$$$only a and b




only a and b

• Question 18

4 out of 4 points

In case-control study, admission rate bias can be avoided by selecting thecontrols from among people admitted to the hospital in the same period of time

but due to other causes. Compared to cases, the probability of admission tohospital for diseases included as controls must be

Answer$

Selected$Answer: $d.$$$Similar

Correct$Answer: $d.$$$Similar

• Question 19

4 out of 4 points


study$design$II.$Bias$results$from$systematic$flaws$in$data$collection$III.$Bias$results$from$systematic$flaws$in$the$analysis$or$interpretation$of$

results$Answer$





• Question 20

4 out of 4 points

The$biggest$threat$to$validity$in$a$clinical$trial$comparing$two$types$of$

treatment$therapy$is$

Answer$




selection$bias


selection$bias

• Question 21

4 out of 4 points



new drug treatment group than the other group, even if not deliberately so.

Answer$

Selected$Answer: $e.$$$none of the above


none of the above

• Question 22

4 out of 4 points

A$RCT$of$10,000$adults$was$conducted$to$determine$if$a$new$antiplatelet$medication$taken$with$aspirin$is$better$than$aspirin$taken$alone$in$

subjects$with$heart$disease.$The$outcome$of$interest$was$MI$(heart$attack).$

Select$the$best$answer:$

Answer$

Selected$

Answer: $b.$$$

It$is$possible$that$effect$modification$by$the$new$anti


Correct$

Answer:

$b.$$$

It$is$possible$that$effect$modification$by$the$new$antiplatelet$medication$could$occur.

• Question 23

4 out of 4 points



Stratification$(stratified$analysis)$and$regression$modeling$(multivariate$

analysis)$are$the$method$for$adjusting$a$confounding$factor$at$the$stage$of$

study$design$$

Answer$

Selected$Answer: $b.$$$false$

Correct$Answer: $b.$$$false$

• Question 24

4 out of 4 points

Confounding bias is the only one of the three types of bias that can becontrolled both in the study design phase and posteriorly in the analytical

phase of an epidemiological study.

Answer$



• Question 25

4 out of 4 points

Cronbach$coefficient$is$used$to$assess$$

Answer$

Selected$Answer: $b.$$$internal$consistency$


internal$consistency$

• Question 26

4 out of 4 points

The$divergence$of$an$observation$on$a$sample$from$the$true$population$

value,$due$to$chance$alone,$is$called$

Answer$




Random$variation

Correct$Answer: $b.$$$Random$variation

• Question 27

4 out of 4 points

The$ROC$curve$is$constructed$by$plotting$$

Answer$

Selected$Answer: $a.$$$Sensitivity$versus$1specificity


Sensitivity$versus$1specificity

• Question 28

4 out of 4 points

Histamine$is$a$mediator$of$inflammation$in$patients$with$allergic$rhinitis.$

Based$on$this$fact,$which$of$the$following$is$true?$

Answer$

Selected$Answer:

$c.$$$


symptoms$(such$as$itching,$sneezing$and$congestion)$should$be$studied$in$patients$with$allergic$rhinitis.

Correct$

Answer: $c.$$$


symptoms$(such$as$itching,$sneezing$and$congestion)$

should$be$studied$in$patients$with$allergic$rhinitis.

• Question 29

4 out of 4 points

A$modern$term$for$the$application$of$clinical$epidemiology$to$the$care$of$patients$is$$



Answer$

Selected$Answers:$ $A.$$$


$

$ Correct$Answers: $A.$$$


$

$

• Question 30

4 out of 4 points

Clinical$epidemiology$is$the$only$basic$science$that$clinicians$rely$on$in$the$care$of$patients.$

Answer$



• Question 1

4 out of 4 points

In much of epidemiological research, the aim of the study is to determine the

effect of a type of exposure upon a given health problem.

Answer$



• Question 2

4 out of 4 points

In general bias can be classified as

Answer$





all of the above

• Question 3

4 out of 4 points


because$$

Answer$





• Question 4

4 out of 4 points

The$inclusion$of$a$large$number$of$subjects$in$a$study$$Answer$





• Question 5

4 out of 4 points

A$variable$is$confounded$if$it$is$directly$along$the$path$from$cause$to$effect.$

Answer$





• Question 6

4 out of 4 points

Chance$can$affect$all$the$steps$involved$in$clinical$research.$

Answer$



• Question 7

4 out of 4 points

All$the$following$methods$for$controlling$a$confounding$factor$are$

applicable$at$the$stage$of$study$design$except:$Answer$

Selected$Answer: $c.$$$stratification


stratification

• Question 8

0 out of 4 points

All$epidemiologic$studies$are$directly$useful$in$the$care$of$individual$patients.$

Answer$



•Question 9

4 out of 4 points

The$ROC$curve$is$constructed$by$plotting$$

Answer$







• Question 10

4 out of 4 points

The comparison of groups is the fundamental element used to establish causal

relationships.

Answer$



• Question 11

4 out of 4 points



Answer$


Vigorous$exercise$

Correct$Answer: $d.$$$Vigorous$exercise$

• Question 12

4 out of 4 points


study$design$II.$Bias$results$from$systematic$flaws$in$data$collection$III.$Bias$results$from$systematic$flaws$in$the$analysis$or$interpretation$of$

results$

Answer$

Selected$Answer: $a.$$$I,$II,$and$III$are$all$true.





• Question 13

4 out of 4 points

Clinical$epidemiology$is$the$application$of$epidemiologic$principles$to$

problems$encountered$in$clinical$medicine.$$Answer$


true$


true$

• Question 14

4 out of 4 points


dependent$variable.$

Answer$

Selected$Answer:$ $False Correct$Answer:$ $False

• Question 15

4 out of 4 points

A$sophisticated$statistical$method$available$to$adjust$simultaneously$for$

various$confounding$factors$$

Answer$


regression$modelling$





• Question 16

4 out of 4 points

The$generalizability$of$clinical$observations,$even$those$with$high$internal$

validity,$is$a$matter$of$personal$judgment$about$which$reasonable$people$might$disagree.$Answer$



• Question 17

4 out of 4 points


Answer$

Selected$Answer:

$d.$$$


status$and$differentially$recall$their$exposure$history$in$a$case$control$study.

Correct$

Answer: $d.$$$


status$and$differentially$recall$their$exposure$history$in$a$case$control$study.

• Question 18

4 out of 4 points

All$the$followings$are$true$except$Answer$

Selected$Answer:

$a.$$$Samples$of$populations$must$have$characteristics$that$are$


Correct$

Answer: $a.$$$





• Question 19

4 out of 4 points

The$ideal$method$of$controlling$confounders$in$a$study$with$a$reasonable$

sample$size$is$$Answer$


randomization$


randomization$

• Question 20

4 out of 4 points

A$bias$arises$from$the$fact$that$those$who$take$medication$generally$differ$

from$those$who$do$not$under$medical$indication.$These$differences$

introduce$a$bias$in$the$comparison.$$

Answer$


Confounding$by$indication$

Correct$Answer: $e.$$$Confounding$by$indication$

• Question 21

4 out of 4 points

Clinical$epidemiology$is$the$only$basic$science$that$clinicians$rely$on$in$the$

care$of$patients.$

Answer$



• Question 22

4 out of 4 points



An investigation in which one group of allergic children receives a new drugtreatment and another receives the usual drug treatment. If the investigator is

also the observer, he or she will tend to be more meticulous in evaluating thenew drug treatment group than the other group, even if not deliberately so.

Answer$


none of the above

Correct$Answer: $e.$$$none of the above

• Question 23

0 out of 4 points

A$mixing$of$effects$between$the$exposure,$the$disease,$and$other$factors$

associated$with$both$the$exposure$and$the$disease$such$that$the$effects$of$

the$two$processes$are$not$separated$is$known$as$$

Answer$

Selected$Answer: $c.$$$effect$modification$


confounding$

• Question 24

4 out of 4 points





results?$$Answer$


Selection bias$




Selection bias$

• Question 25

4 out of 4 points



Answer$



• Question 26

4 out of 4 points

Bias occurs when the cases and/or controls are recruited from amonghospitalized patients.

Answer$



• Question 27

4 out of 4 points




Answer$


Similar




Similar

• Question 28

4 out of 4 points

There$is$a$positive$association$between$carrying$matches$and$lung$cancer.$This$is$an$example$of$an$association$likely$caused$by:$

Answer$

Selected$Answer: $c.$$$confounding$factor


confounding$factor

• Question 29

4 out of 4 points

When the magnitude of the bias is related to exposure to the study factor on the part of the subject or the condition of his or her disease.

Answer$





• Question 30

4 out of 4 points

The$effects$of$bias$and$chance$are$

Answer$

Selected$Answer: $c.$$$Cumulative

Correct$Answer: $c.$$$Cumulative



• Question 1

4 out of 4 points

Different drug classes have been recommended in the control of

hyperglycaemia and prevention of diabetes complications. To this end,diabetes is associated with multiple risk factors for complications and thus,

subjects requiring drug treatment are often high risk individuals for hypertension, CVD, renal disease and cancer. Thus, drug use indication bias is

a systematic error due to$Answer$

Selected$Answer: $$$$

Selection bias

Correct$Answer: $$$$

Selection bias

• Question 2

4 out of 4 points


Answer$

Selected$

Answer: $a.$$$

A$study$can$be$internally$valid$but$not$externally$valid



valid

• Question 3

4 out of 4 points

The$inclusion$of$a$large$number$of$subjects$in$a$study$$

Answer$

Selected$Answer: $b.$$$Allows$precise$risk$estimates$to$be$calculated$





• Question 4

0 out of 4 points

We$wish$to$investigate$if$a$new$drug$is$effective$in$reducing$the$duration$

and$severity$of$the$migrain$headache.$We$take$the$next$15$patients$that$come$to$the$walkin$clinic$and$tell$them$about$the$new$drug$we$are$giving$

them$and$we$give$them$the$new$drug$.$Twelve$patients$state$the$new$drug$

was$helpful$in$reducing$the$severity$and$duration$of$migrain$headache.$

Which$of$the$following$is$NOT$CORRECT?$

Answer$

Selected$Answer:

$b.$$$

This$is$not$a$good$clinical$trial$because$it$is$not$double

blinded.$The$patients$may$feel$relief$because$they$thought$

the$new$drug$should$work.

Correct$

Answer: $d.$$$

This$is$not$a$good$clinical$trial$because$we$didn$t$give$the$

new$drug$to$subjects$without$migrain$headache$to$assess$

its$effect$in$a$control$group

• Question 5

4 out of 4 points

There$is$a$positive$association$between$carrying$matches$and$lung$cancer.$

This$is$an$example$of$an$association$likely$caused$by:$Answer$


confounding$factor

Correct$Answer: $c.$$$confounding$factor

• Question 6

4 out of 4 points




study$design$II.$Bias$results$from$systematic$flaws$in$data$collection$III.$

Bias$results$from$systematic$flaws$in$the$analysis$or$interpretation$of$

results$

Answer$





• Question 7

4 out of 4 points

The comparison of groups is the fundamental element used to establish causalrelationships.

Answer$



• Question 8

4 out of 4 points


Answer$

Selected$Answer: $c.$$$Cumulative


Cumulative

• Question 9

4 out of 4 points

A bias that affects all the comparator groups equally and tends to dilute thetrue existing association

Answer$




Non-differential information bias

Correct$Answer: $b.$$$ Non-differential information bias

• Question 10

4 out of 4 points

There$are$sharp$distinctions$among$the$biologic$sciences$(such$as$anatomy$and$physiology).$$

Answer$



• Question 11

4 out of 4 points


value,$due$to$chance$alone,$is$called$

Answer$

Selected$Answer: $b.$$$Random$variation


Random$variation

• Question 12

4 out of 4 points

All$epidemiologic$studies$are$directly$useful$in$the$care$of$individual$patients.$

Answer$





• Question 13

4 out of 4 points

The$degree$to$which$the$results$of$a$study$are$correct$for$the$sample$of$

patients$being$studied$is$called$$Answer$


internal$validity$


internal$validity$

• Question 14

4 out of 4 points


Answer$

Selected$

Answer: $d.$$$



case$control$study.

Correct$Answer:

$d.$$$It$occurs$when$cases$and$controls$know$their$outcome$


case$control$study.

• Question 15

4 out of 4 points

Good$decisions$depend$on$$

Answer$


all$of$the$above$


all$of$the$above$



• Question 16

4 out of 4 points

A type of bias occurs when we study a disease that causes early death, and at

the start of the study the deceased individuals can no longer be included in thecase group.

Answer$

Selected$Answer: $a.$$$ Neyman bias

Correct$Answer: $a.$$$ Neyman bias

•Question 17

4 out of 4 points

Bias occurs when the cases and/or controls are recruited from among

hospitalized patients.

Answer$



• Question 18

4 out of 4 points


Answer$



Correct$Answer: $a.$$$Differential information bias

• Question 19



4 out of 4 points





results?$$

Answer$

Selected$Answer: $a.$$$Selection bias$


Selection bias$

• Question 20

4 out of 4 points


because$$Answer$





• Question 21

4 out of 4 points

All systematic errors can be controlled in the phase corresponding to analysisof the results.

Answer$





• Question 22

0 out of 4 points

The$study$of$how$nonbiologic$factors$affect$patients'$health$is$known$as$$

Answer$


sociology


health$service$research

• Question 23

4 out of 4 points

The$degree$to$which$the$results$of$an$observation$hold$true$in$other$settings$is$$

Answer$


generalizability

Correct$Answer: $d.$$$generalizability

• Question 24

4 out of 4 points


problems$encountered$in$clinical$medicine.$$

Answer$


true$

Correct$Answer: $a.$$$true$

• Question 25

4 out of 4 points



Random error

Answer$

Selected$Answer: $e.$$$Does not always occur in the same direction.$


Does not always occur in the same direction.$

• Question 26

4 out of 4 points

A confounding factor may or may not carry some causal relationship to the

outcome.

Answer$

Selected$Answer: $A.$$$

true

Correct$Answer: $A.$$$

true

• Question 27

0 out of 4 points

A$bias$occurs$when$comparisons$are$made$between$groups$of$patients$

that$differ$in$determinants$of$outcome$other$than$the$one$under$study.$

Answer$


confounding$bias

Correct$Answer: $b.$$$selection$bias

• Question 28

4 out of 4 points





Answer$





• Question 29

4 out of 4 points


analysis)$are$the$method$for$adjusting$a$confounding$factor$at$the$stage$of$study$design$$

Answer$


false$


false$

• Question 30

4 out of 4 points


remember, their eating habits during pregnancy than women with healthychildren. This is an example of

Answer$

Selected$Answer: $c.$$$Differential information bias



• Question 1

4 out of 4 points




Answer$


Correct$Answer: $d.$$$all of the above

• Question 2

4 out of 4 points

A$RCT$of$10,000$adults$was$conducted$to$determine$if$a$new$antiplatelet$

medication$taken$with$aspirin$is$better$than$aspirin$taken$alone$in$

subjects$with$heart$disease.$The$outcome$of$interest$was$MI$(heart$attack).$Select$the$best$answer:$

Answer$

Selected$

Answer: $b.$$$

It$is$possible$that$effect$modification$by$the$new$anti


Correct$

Answer: $b.$$$

It$is$possible$that$effect$modification$by$the$new$antiplatelet$medication$could$occur.

• Question 3

0 out of 4 points


Answer$

Selected$Answer: $a.$$$ Neyman bias

Correct$Answer: $c.$$$ Non-response bias

• Question 4

4 out of 4 points



Confounding bias is the only one of the three types of bias that can be

controlled both in the study design phase and posteriorly in the analytical phase of an epidemiological study.

Answer$



• Question 5

4 out of 4 points



Answer$

Selected$Answer: $d.$$$Vigorous$exercise$


Vigorous$exercise$

• Question 6

4 out of 4 points




Answer$

Selected$Answer: $d.$$$Similar


Similar

• Question 7

4 out of 4 points





Answer$



Correct$Answer: $c.$$$regression$modelling$

• Question 8

0 out of 4 points

Quantitative$decision$analysis$include$$

Answer$


decision$analysis$


a$$and$c$

• Question 9

4 out of 4 points



new drug treatment group than the other group, even if not deliberately so.

Answer$


none of the above

Correct$Answer: $e.$$$none of the above

• Question 10

4 out of 4 points




analysis)$are$the$method$for$adjusting$a$confounding$factor$at$the$stage$of$

study$design$$

Answer$


false$


false$

• Question 11

4 out of 4 points

In much of epidemiological research, the aim of the study is to determine the

effect of a type of exposure upon a given health problem. Answer$



• Question 12

4 out of 4 points

Selection bias is more common inAnswer$

Selected$Answer: $a.$$$cross-sectional studies


cross-sectional studies

• Question 13

4 out of 4 points

Chance$can$affect$all$the$steps$involved$in$clinical$research.$

Answer$





• Question 14

4 out of 4 points


dependent$variable.$Answer$



• Question 15

4 out of 4 points

There$are$sharp$distinctions$among$the$biologic$sciences$(such$as$anatomy$and$physiology).$$

Answer$



• Question 16

4 out of 4 points


problems$encountered$in$clinical$medicine.$$

Answer$


true$


true$

• Question 17

4 out of 4 points


value,$due$to$chance$alone,$is$called$Answer$




Random$variation

Correct$Answer: $b.$$$Random$variation

• Question 18

4 out of 4 points

Women with allergic children will remember better, or make a greater effort toremember, their eating habits during pregnancy than women with healthy

children. This is an example of

Answer$

Selected$Answer: $d.$$$Differential information bias

Correct$Answer: $d.$$$Differential information bias

• Question 19

4 out of 4 points

A type of bias occurs when we study a disease that causes early death, and atthe start of the study the deceased individuals can no longer be included in the

case group.

Answer$


Neyman bias


Neyman bias

• Question 20

4 out of 4 points


Answer$



Selected$

Answer: $a.$$$


valid



valid

• Question 21

4 out of 4 points

The comparison of groups is the fundamental element used to establish causal

relationships.

Answer$



• Question 22

4 out of 4 points



Answer$



• Question 23

4 out of 4 points

The$clinical$events$of$primary$interest$in$clinical$epidemiology$are$

Answer$


symptoms,$disability,$and$death

Correct$Answer: $c.$$$symptoms,$disability,$and$death



• Question 24

4 out of 4 points

The$gene$for$phenylketon$uria$is$expressed$only$in$children$who$ingest$

phenylalanine$in$their$diet.$Answer$



• Question 25

4 out of 4 points


Answer$



Correct$Answer: $a.$$$Differential information bias

•Question 26

4 out of 4 points


Answer$


Cumulative


Cumulative

• Question 27

4 out of 4 points




Answer$


only a and b

Correct$Answer: $e.$$$only a and b

• Question 28

4 out of 4 points

The$generalizability$of$clinical$observations,$even$those$with$high$internal$

validity,$is$a$matter$of$personal$judgment$about$which$reasonable$people$might$disagree.$

Answer$ Selected$Answer:$ $True


• Question 29

4 out of 4 points

The$biggest$threat$to$validity$in$a$clinical$trial$comparing$two$types$of$

treatment$therapy$is$Answer$

Selected$Answer: $e.$$$selection$bias

clinical epidemiology complete

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