Evidence-Based Medicine (Evidence-Based Medicine (EBMEBM):):What does it really mean?What does it really mean?

Presented byPresented by

Dr khamis Elessi Dr khamis Elessi BSc, MD, BSc, MD, MSc, DipAcuMSc, DipAcu

Board in rehab. medicineBoard in rehab. medicine

Ahmad, is a 40y/o patient referred to you as the Ahmad, is a 40y/o patient referred to you as the doctor in charge after seeing a neurologist and was doctor in charge after seeing a neurologist and was previously prescribed pregabalin 150 mg BID for the previously prescribed pregabalin 150 mg BID for the treatment of spasticity.treatment of spasticity.

Never heard of it? Now as doctor in charge, what do Never heard of it? Now as doctor in charge, what do you do?you do?

1.1. Prescribe another drug that you are familiar with?Prescribe another drug that you are familiar with?2.2. Call the referring Doctor?Call the referring Doctor?3.3. Call your Senior?Call your Senior?4.4. Search for the drug on the internet?Search for the drug on the internet?5.5. Just continue with the drug?Just continue with the drug?

Traditional Sources of Medical Traditional Sources of Medical InformationInformation

Internet Internet Colleagues / PatientsColleagues / PatientsConferencesConferencesDrug RepsDrug RepsTextbooksTextbooksJournalsJournals

““Evidence-based medicine is the Evidence-based medicine is the conscientious, explicit, & judicious conscientious, explicit, & judicious use of use of best available evidencebest available evidence in in making decisions about the care making decisions about the care of of individual patientsindividual patients””

David Sackett, 1996David Sackett, 1996

Original “Official” Definition of EBM

EBM Can improve:EBM Can improve:Medical and Nursing care for Patient.Medical and Nursing care for Patient.Quality of Clinical CareQuality of Clinical CarePublic Health in generalPublic Health in general

Overall goal is Improving the quality of Overall goal is Improving the quality of patients’ lives…patients’ lives…

Principles of EBMPrinciples of EBM

EBM has 2 fundamentals principles EBM has 2 fundamentals principles 1.1.Hierarchy of EvidenceHierarchy of Evidence2.2.Insufficiency of Evidence aloneInsufficiency of Evidence alone

Hierarchy of Evidence: Things to ConsiderHierarchy of Evidence: Things to Consider

EBM is only as good as EBM is only as good as the data availablethe data available

A quality case-control A quality case-control study is more meaningful study is more meaningful than a flawed RCTthan a flawed RCT

Thus, systematic reviews Thus, systematic reviews of RCTs are not of RCTs are not necessarily best evidencenecessarily best evidence

Insufficiency of Evidence aloneInsufficiency of Evidence aloneEvidence is never enough alone but needs to Evidence is never enough alone but needs to

be coupled with clinical experience and patient be coupled with clinical experience and patient choices & valueschoices & values

EvidenceEvidenceExpertiseExpertiseExpectationExpectation

Why is EBM important?Why is EBM important?New types of evidence are being generated which can create changes in the way patients are treated

Although evidence is needed on a daily basis, usually physicians don’t get it due to

1.Lack of time 2.Out-of-date textbooks, and 3.Disorganization of the up-to-date journals

Too many articles are inconsistent, even contradictoryToo many articles are inconsistent, even contradictory Most reviews are not systematic; instead are subjectiveMost reviews are not systematic; instead are subjective

Why we Need to learn EBMWhy we Need to learn EBM• There is big gap between research and practiceThere is big gap between research and practice• There are Wide variations in clinical practice There are Wide variations in clinical practice • ~40% of clinical decisions not supported by any strong ~40% of clinical decisions not supported by any strong

evidenceevidence• Many Ineffective treatments are adopted/maintainedMany Ineffective treatments are adopted/maintained

• Pharmaceutical companies influence clinical decisions Pharmaceutical companies influence clinical decisions • Over-reliance on clinical experience & expert opinionOver-reliance on clinical experience & expert opinion

• There are Concerns about cost & quality in medicineThere are Concerns about cost & quality in medicine• To avoid medico-legal suitsTo avoid medico-legal suits

Why bother with EBM?Why bother with EBM? The amount of information is growing exponentially, The amount of information is growing exponentially, but our attention is not.but our attention is not.

The low cost of production of poor quality information The low cost of production of poor quality information results in high quality information being drowned out.results in high quality information being drowned out.

Too muchToo much information creates a poverty of attention. information creates a poverty of attention.

The cost of finding specific information rises as the The cost of finding specific information rises as the amount of information increases.amount of information increases.

Too many journals/articles / Too many journals/articles / no time to readno time to read

Review the World Literature Fortnightly*Review the World Literature Fortnightly* *"Kill as Few Patients as Possible" - Oscar London *"Kill as Few Patients as Possible" - Oscar London

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A shocking newsA shocking newsNew knowledge evolves very quickly. New knowledge evolves very quickly.

Medical school knowledge quickly becomes outdated and/or forgotten.

Half of what you are taught as medical students Half of what you are taught as medical students will have been shown in ten years to be wrong. will have been shown in ten years to be wrong. And the trouble is none of your teachers know And the trouble is none of your teachers know which half,” said which half,” said Dr. Sydney Burwell, Dean of Dr. Sydney Burwell, Dean of Harvard Medical school.Harvard Medical school.

Sample of Information RetentionSample of Information Retention

A study showed that about 50% read only 1 Hr/week So, other half read more than 1 Hr/week

Examples of our ignorance of Examples of our ignorance of EvidenceEvidence

Corticosteroid for preterm Birth Corticosteroid for preterm Birth ( P5)( P5)Corneal PatchingCorneal PatchingSIDSSIDSArryhthmia suppressionArryhthmia suppression

Ecainide/flecainide Ecainide/flecainide (P6)(P6)Arrhythmia suppressionArrhythmia suppressionRCT increased mortalityRCT increased mortalityDisease specific vs. patient specific outcomesDisease specific vs. patient specific outcomes

Patching corneal abrasion compared Patching corneal abrasion compared with placebowith placebo

The standard practice of both family physicians & The standard practice of both family physicians & ophthalmologists has always been to patch the eyes ophthalmologists has always been to patch the eyes of patients with simple uncomplicated Corneal of patients with simple uncomplicated Corneal abrasions as well as prescribing mydriatic agent and abrasions as well as prescribing mydriatic agent and antibiotics eye drops.. antibiotics eye drops..

However, no one ever asked if patching was However, no one ever asked if patching was beneficial, It was just common sense.beneficial, It was just common sense.

There has been at least 5 RCT’s of patch VS no patch There has been at least 5 RCT’s of patch VS no patch and each has come up with the same answer.and each has come up with the same answer.

patches offer no benefit and may ever slow down the patches offer no benefit and may ever slow down the healing process and increase patients discomfort.healing process and increase patients discomfort.

Prevention of SIDS…”Back to Sleep” Prevention of SIDS…”Back to Sleep”

Doctors I western countries traditionally Doctors I western countries traditionally recommend that babies sleep on their recommend that babies sleep on their stomach.stomach.

It was thought tat by sleeping on their back It was thought tat by sleeping on their back infants at risk of regurgitation & aspiration infants at risk of regurgitation & aspiration leading to SIDS. leading to SIDS.

In 1980’s, some MD’s asked the question, is In 1980’s, some MD’s asked the question, is there any evidence to support the practice there any evidence to support the practice of sleeping infants on their stomach?.of sleeping infants on their stomach?.

Prevention of SIDS…”Back to Prevention of SIDS…”Back to Sleep” Sleep”

As it turn out case control & Ecological As it turn out case control & Ecological studies found dramatic decrease among I studies found dramatic decrease among I children who sleeps o their backs leading children who sleeps o their backs leading to the national “to the national “Back to Sleep” programBack to Sleep” program..

Had some one asked the question 20 Had some one asked the question 20 years earlier, tens of thousands of lives years earlier, tens of thousands of lives might have been saved.might have been saved.

higher need for EBM !!!!higher need for EBM !!!! in 1994 17% of family Practitioners thought that in 1994 17% of family Practitioners thought that

aspirin had no effect on the survival of patients aspirin had no effect on the survival of patients having an MI & stroke (having an MI & stroke (evidence was available evidence was available from1988from1988) .) .

LBP & Disc Sx !!!! LBP & Disc Sx !!!!

Many Variation in prescribing, diagnostic tests, Many Variation in prescribing, diagnostic tests, management of chronic conditions (DM, HTN).management of chronic conditions (DM, HTN).

How to apply EBM?How to apply EBM?• It may be argued that MDs and other health care It may be argued that MDs and other health care

providers have always used & continue to use providers have always used & continue to use evidence, expertise & Px values in decision making. evidence, expertise & Px values in decision making.

• This may be true for very good MDs. The difference This may be true for very good MDs. The difference lies in emphasis, rigor and understanding.lies in emphasis, rigor and understanding.

• The 4 steps model for accessing, appraising evidence, The 4 steps model for accessing, appraising evidence, which make the process easy & more systematic.which make the process easy & more systematic.

• It may help you refine some of the pre-EBM notions It may help you refine some of the pre-EBM notions and concepts you used to have.and concepts you used to have.

Steps in Practicing EBMSteps in Practicing EBM1.1. Ask Ask specific specific question to reach the required question to reach the required

informationinformation2.2. Acquire the best available evidence with Acquire the best available evidence with

which you can answer that question.which you can answer that question.3.3. Critically Appraise that evidence for its Critically Appraise that evidence for its

validity, impact, and applicability. validity, impact, and applicability. → Decision→ Decision4.4. Apply the evidence with your clinical Apply the evidence with your clinical

expertise & patient’s preferences & values.expertise & patient’s preferences & values.

Clinical QuestionsClinical QuestionsBackground - “What is it?”Background - “What is it?”

General information on a condition or diseaseGeneral information on a condition or diseaseForeground – “What do I do for this patient?”Foreground – “What do I do for this patient?”

PatientPatient Intervention/InvestigationIntervention/InvestigationComparison Intervention/InvestigationComparison Intervention/InvestigationOutcome (Patient-Oriented)Outcome (Patient-Oriented)

The ‘PICO’ principle Questions are often vaguely formulated, which makes

finding answers in the medical literature a challenge. Properly structured question will make it easy to find

answers which is an essential first step in EBP.

Most questions can be divided into four components: P =Population and clinical problem I =Intervention or “exposure”or “exposure”(indicator or index)* C =Comparator O =Outcome (diagnosis/screening, prognosis, therapy, (diagnosis/screening, prognosis, therapy,

event, harm, or prevention)event, harm, or prevention)

How To Structure How To Structure Clinical QuestionsClinical Questions

PP – Patient population / problem – Patient population / problemWhat are you trying to address What are you trying to address Does gender/age influence clinical careDoes gender/age influence clinical care

II - Intervention / Area of interest - Intervention / Area of interestWhat will you do for the patient?What will you do for the patient?Drugs, surgery, diet, exerciseDrugs, surgery, diet, exercise

CC – Comparison intervention / status – Comparison intervention / statusAlternatives to your chosen intervention? Alternatives to your chosen intervention? Against other interventions, gold standard, or no treatmentAgainst other interventions, gold standard, or no treatment

OO – Measurable outcome of interest – Measurable outcome of interest What will be improved for the patient?What will be improved for the patient?Less risk of fracture, fewer hospitalizations, etc.Less risk of fracture, fewer hospitalizations, etc.

Filtering the Evidence: Filtering the Evidence: The “Big Four”The “Big Four”

Diagnosis question Diagnosis question How well does it How well does it confirm or exclude a diagnosisconfirm or exclude a diagnosis??

Therapy question Therapy question Does it Does it do more gooddo more good than harm? than harm?

Etiology question Etiology question How well does it How well does it identify a cause identify a cause for a disease?for a disease?

Prognosis question Prognosis question How well does it How well does it predictpredict clinical course over time? clinical course over time?

How To Structure Clinical QuestionsHow To Structure Clinical QuestionsPreferred design to answer different questionsPreferred design to answer different questions

Clinical Questions - “PICO”Clinical Questions - “PICO”

Example 1:Example 1: In a 5 year old child with conjunctivitis (In a 5 year old child with conjunctivitis (patientpatient) will ) will

topical antibiotics (topical antibiotics (interventionintervention) compared to no ) compared to no treatment (treatment (comparisoncomparison) lead to quicker symptom ) lead to quicker symptom relief (relief (outcomeoutcome)?)?

Example 2Example 2

Steps in Practicing “Steps in Practicing “PullPull” EBM” EBM1.1. Ask Ask specific specific question to reach the required question to reach the required

informationinformation2.2. Acquire the best available evidence with Acquire the best available evidence with

which you can answer that question.which you can answer that question.3.3. Critically Appraise that evidence for its Critically Appraise that evidence for its

validity, impact, and applicability. validity, impact, and applicability. → Decision→ Decision4.4. Apply the evidence with your clinical Apply the evidence with your clinical

expertise & patient’s preferences & values.expertise & patient’s preferences & values.

Evidence Pyramid: Types of information(Quality of Evidence)

Filtered Information Filtered Information Systematic Reviews/ Meta-Analyses Systematic Reviews/ Meta-Analyses Critically-Appraised Topics (Synthesis) Critically-Appraised Topics (Synthesis) Critically-Appraised Articles (Synopsis)Critically-Appraised Articles (Synopsis)

Unfiltered Information Unfiltered Information Randomized Controlled Trials Randomized Controlled Trials Cohort Studies Cohort Studies Case-Controlled Studies/Case Series and Reports Case-Controlled Studies/Case Series and Reports Background Info(Textbooks)/Expert OpinionBackground Info(Textbooks)/Expert Opinion

Steps in Practicing “Steps in Practicing “PullPull” EBM” EBM1.1. Ask Ask specific specific question to reach the required question to reach the required

informationinformation2.2. Acquire the best available evidence with Acquire the best available evidence with

which you can answer that question.which you can answer that question.3.3. Critically Appraise that evidence for its Critically Appraise that evidence for its

validity, impact, and applicability. validity, impact, and applicability. → Decision→ Decision4.4. Apply the evidence with your clinical Apply the evidence with your clinical

expertise & patient’s preferences & values.expertise & patient’s preferences & values.

Step 3: Critically appraise the evidence (cont.)Step 3: Critically appraise the evidence (cont.)

There are 4 issues in critical appraisal:There are 4 issues in critical appraisal:

RelevanceRelevance: refers to the extent to which the research : refers to the extent to which the research paper matches your needs.paper matches your needs.

Validity:Validity: is the extent to which the results are free is the extent to which the results are free from bias. (selection Bias, Randomization, from bias. (selection Bias, Randomization, Measurement bias, Analysis biasMeasurement bias, Analysis bias

Consistency:Consistency: refers to the extent to which the results refers to the extent to which the results are similar across different analysis in the study & are are similar across different analysis in the study & are in agreement with evidence from other studiesin agreement with evidence from other studies

Importance & significance of ResultsImportance & significance of Results ( analyzed in ( analyzed in light of type of Studylight of type of Study

Step 3: Critically appraise the evidence (cont.)Step 3: Critically appraise the evidence (cont.)

Critique requires knowledge of basic epidemiology (study designs) Critique requires knowledge of basic epidemiology (study designs) and biostatistics: and biostatistics:

ASSUMING you have the right study design:ASSUMING you have the right study design: Check appropriate sample size, randomization, treatment Check appropriate sample size, randomization, treatment

allocation, analysis, etc. allocation, analysis, etc. Sensitivity, specificity, prevalence, likelihood ratiosSensitivity, specificity, prevalence, likelihood ratios Absolute risk reduction, relative risk reduction, odds ratios, Absolute risk reduction, relative risk reduction, odds ratios,

number needed to treat, numbers needed to harm.number needed to treat, numbers needed to harm.

General Rule:General Rule: Meta-analysis of RCT’s > RCT > Cohort > Case Control > Case Meta-analysis of RCT’s > RCT > Cohort > Case Control > Case

Series > Case Report.Series > Case Report. Retrospective studies weaker than prospective studiesRetrospective studies weaker than prospective studies

Step 4: Step 4: Steps in Practicing EBMSteps in Practicing EBM1.1. Ask Ask specific specific question to reach the required question to reach the required

informationinformation2.2. Acquire the best available evidence with Acquire the best available evidence with

which you can answer that question.which you can answer that question.3.3. Critically Appraise that evidence for its Critically Appraise that evidence for its

validity, impact, and applicability. validity, impact, and applicability. → Decision→ Decision4.4. Apply the evidence with your clinical Apply the evidence with your clinical

expertise & patient’s preferences & values.expertise & patient’s preferences & values.

Making best practice decision Making best practice decision requires sound judgment requires sound judgment based on the integration of based on the integration of

best research evidencebest research evidenceClinical expertise Clinical expertise Patient’s valuesPatient’s values

As patient participates in As patient participates in care decisions, you are care decisions, you are practicing TRUE evidence practicing TRUE evidence based medicinebased medicine

Applying EBM helps you Make best decisions in medicine

Final advises on EBMFinal advises on EBM Be ready to “surrender” to a better evidence when Be ready to “surrender” to a better evidence when

found.found. Do not become entrenched in what has been done for Do not become entrenched in what has been done for

yearsyears A bad idea done by MANY for LONG time, still baddeaA bad idea done by MANY for LONG time, still baddea Not all claims to be “evidence based”, is really EBMNot all claims to be “evidence based”, is really EBM Use High quality sources (Use High quality sources (Cochrane, AHRQ, ACP Cochrane, AHRQ, ACP

Journal Club, Clinical Evidence, InfoRetriever.Journal Club, Clinical Evidence, InfoRetriever. Retrospective studies weaker than prospective studiesRetrospective studies weaker than prospective studies Discard Questionable results developed by poor Discard Questionable results developed by poor

methodologymethodology