Introduction to

Evidence based medicine

(EBM)

Badr Mesbah

Pediatrics Department and Clinical Epidemiology Unit Faculty of Medicine, Suez Canal University

What is evidence-based medicine?

• …an approach to practicing medicine in which

the clinician is aware of the evidence in support

of clinical practice, and the strength of that

evidence.

What is evidence-based medicine?

• Combines your clinical knowledge with your

knowledge of your patient, with evidence from

the literature

What is evidence-based medicine?

• Evidence-based medicine is the integration of best research evidence with clinical expertise and patient values”

Sackett DL, Rosenberg WMC, Gray JAM, Haynes RB, Richardson WS: Evidence based medicine: what it is and what it isn’t. BMJ 1996;312:71-2

Patient Concerns

Clinical Expertise

Best research evidence

EBM

Why EBM?

• Daily need for information

• Inadequacy of traditional sources of information

• Disparity between our diagnostic skills and clinical judgment vs. up-to-date knowledge and clinical performance

• Develop skills for lifelong learning

Steps to practice EBM

• Convert clinical questions into a searchable format.

• Search for evidence.

• Critically assess the information for validity and usefulness.

Steps to practice EBM

• Apply the information in clinical practice.

• Evaluate the performance of the information in clinical practice.

• Discover areas where more research is needed

The first step of EBM

• Convert a clinical situation into a searchable, (and hopefully answerable) question using

PICO•PATIENT

•INTERVENTION

•COMPARISON

•OUTCOME

PICO

PPatientatient

Intervention

Comparison

Outcome

“Patient” refers to the person presenting with the problem, or more simply, to the problem itself. Both concepts are important in searching.

PICO

Patient

IInterventionntervention

Comparison

Outcome

“Intervention” refers to the action taken in response to the problem. This is often a drug or surgical procedure, but it can take many forms

PICO

Patient

Intervention

CComparisonomparison

Outcome

“Comparison” refers to the benchmark against which the intervention is measured. Often it refers to another treatment, no treatment, or a placebo

PICO

Patient

Intervention

Comparison

OOutcomeutcome“Outcome” refers to the anticipated result of the intervention.

Search for evidence

• Types of Information Databases• Primary sources

– MedLine– Require more work to validate

• Secondary sources– Cochrane, Best Evidence, InfoPoems– Already reviewed - less work to validate– Limited amount of information studied

How good is the evidence?

- Is it from a peer-reviewed journal?

- Is the location and patients similar to mine?

- Sponsored by an organization that may influence

the study design or results?

- Will the information, if true, have an impact on

my patients and practice?

Study pyramid

Best

Worst

Levels of Evidences

• (I-1): a well done systematic review of 2 or more RCTs • (I-2): a RCT • (II-1): a cohort study• (II-2): a case-control study• (II-3): a dramatic uncontrolled experiment• (III): respected authorities, expert committees, etc.. • (IV): ...someone once told me....

Yalla, let’s try

Clinical Scenario

A family came with their 3 days old baby: We want to perform circumcision to our baby as his pain perception is minimal at this age. You know that this is not true and wondered about the best method of pain relief in this situation

Question (PICO)

Patients:

Intervention:

Comparison:

Outcome:

Newborn undergoing circumcision

Pharmacological and/or nonpharmacologicalinterventions

No intervention

Pain relief

Question

• In newborn infants undergoing circumcision (population), which pharmacological and/or non-

pharmacological interventions (intervention) provide the best pain relief (outcome)?

Search for evidence

Intervention Type of evidence Results Comments

Paracetamol versus placebo

Systematic reviews Paracetamol is effective in reducing postoperative pain

Benefit was noted only 6 hours after surgery

Dorsal penile nerve block versus no intervention

Systematic review Dorsal penile nerve block is effective in reducing painresponse

Bruising and/or hematoma canoccur at the site of injection

Search for evidence

Intervention Type of evidence Results Comments

Ring block versus no intervention

Systematic reviews Ring block is effective inreducing pain response

Further studies of ring block arerequired to demonstrate anysuperiority in efficacy andsafety compared to dorsal penile nerve block

EMLA versus nointervention

Systematic review EMLA decreases pain response

EMLA cannot be recommendedover local regional nerve block

Search for evidence

Intervention Type of evidence Results Comments

Sucrose with or without pacifier compared to waterwith or without pacifier

Systematic reviews Oral sucrose with or without pacifier is effective in reducing the pain response

Sucrose is not as effective asdorsal penile nerve block

Swaddling versus nointervention

Systematic review Swaddling reduces behavioralresponse

Current best practice for reducing pain associated with circumcision

• Administer 10–15 mg kg of acetaminophen within 2 hours before the procedure and every 4–6 hours

for 24 hours after the procedure.

• Offer a sucrose-dipped pacifier to the newborn before the dorsal penile nerve block, during the circumcision procedure, and after

Current best practice for reducing pain associated with circumcision

• Administer dorsal penile nerve block using lidocaine

• Swaddle the infant’s upper body during the circumcision

Future research needs • Further research is required to find ways to

reduce the exposure of newborns to painful stimuli and to refine the pain management for unavoidable, painful, medically indicated procedures..

Do developing countries really need EBM?

Definitely yes, more so than in Western world• Limited resources even more precious• Waste even more unacceptable when needs are great and budgets small• Often there is evidence that current practices

don’t work and should be abandoned• Best evidence doesn’t mean perfect evidence,

rather best available; solutions need to be appropriate for setting and resources

Summary• Evidence-based medicine is a systematic

approach to use up to date information in the practice of medicine

• Skills are needed to integrate the available evidence with clinical experience and patient concerns

• Application and evaluation of EBM skills will provide a framework for life-long learning.

Badr Mesbah

Thank you