Evidence-Based Medicine

“Hai orang-orang yang beriman, jika datang kepadamu orang fasik membawa suatu berita, maka periksalah (kebenarannya) dengan teliti, agar kamu tidak menimpakan suatu musibah kepada suatu kaum tanpa mengetahui keadaannya yang menyebabkan kamu menyesal atas perbuatanmu itu”. (Al-Hujurat: 6)

ObjectivesBackgroundRoleDefiniton and AimComponentsStepsLevel EvidenceMain Area Introduction(diagnosis, therapy,

prognosis, harm)

Two fundamental questions…What is the purpose of medicine?How do I decide what to do?

You have to know where you’re going before deciding how to get there…

What is the purpose of medicine?

Patient carePublic healthResearch

Improving the quality of patients’ lives…

What is evidence-based medicine?

Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions

about the care of individual patients.

Sackett, et al. BMJ 1996;312:71-72

Old paradigm

Unsystematic clinical experience

Pathophysiology

Content expertise & authoritarianism

New paradigm

Systematic clinical experience

Pathophysiology necessary but not sufficient

Rules of evidence

Practice PradigmsPractice Pradigms

backgorundEBM is relatively new. The term EBM became more widely used in the early 1990s, and was later formally defined by Sackett et al. in 1996.

The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research

Rolefinding evidence and using that evidence to

make clinical decisionsA cornerstone of EBM is the hierarchical

system of classifying evidence. This hierarchy is known as the levels of

evidence. Physicians are encouraged to find the highest level of evidence to answer clinical questions.

Definiton "Evidence-based medicine is the

integration of best research evidence with clinical expertise and patient values." 

Sackett, D. L. (2000). Evidence-based medicine: How to practice and teach EBM(2nd ed.). Edinburgh; New York: Churchill Livingstone.

Clinical expertise: the clinician’s cumulated experience, education, and clinical skills

Patient values: The patient brings to the encounter his or her own personal and unique concerns, expectiations, and values.

Best Research Evidence: usually found in clinically relevant research that has been conducted using sound methodology

Evidence-Based Medicine (EBM)Evidence-Based Practice (EBP)Evidence-Based Clinical Practice (EBCP)Evidence-Based Health Care (EBHC) Evidence-Based Nursing (EBN)

Sackett’s definition refers to all of these;EBP and EBHC are more universally

used.

EBP:1.Assess the patient2.Ask the question3.Acquire the evidence4.Appraise the

evidence5.Apply: talk with the

patient(from Introduction to Evidence

Based Practice tutorial)

EBM:1. Ask focused

question2. Find the evidence3. Appraise the

evidence4. Make a decision5. Evaluate

performance(from Centre for Evidence Based

Medicine www.cebm.net)

Levels of evidenceLevel Type of evidence

I Evidence obtained from at least one randomised controlled trial or from meta-analysis of randomised controlled trials

II Evidence obtained from at least one well-designed controlled study without randomisation

III Evidence obtained from well-designed non-experimental descriptive studies, such as comparative studies, correlation studies and case control studies

IV Evidence obtained from expert committee reports or opinions and/or clinical experience of respected authorities

Forming a question

Identify key patient problemPhrased to facilitate finding an answer

What treatment might be considered

Alternative treatments to considerOutcome to avoid or promote

PICOP= Patient or problemI = Intervention, prognostic factor, or exposure

C=ComparisonO=Outcomes(T)=Type of Study

Exercises: PICO scenarios

Types of StudiesCase series and Case ReportsCase control studiesCohort studiesRandomized, controlled clinical trials

Systematic ReviewsMeta-analysis

Case series and Case reports

Collections of reports on the treatment of individual patients or a report on a single patient.

No control groups with which to compare outcomes, so limited statistical validity.

Case control studies

Patients who already have a specific condition are compared with people without the condition. Researcher looks back to identify factors or exposures possibly associated with the condition, often relying on medical records and patient recall.

Less reliable because showing a statistical relationship does not mean than one factor necessarily caused the other. 

Starts with patients who already have the outcome and looks backwards to possible exposures.

Cohort studies

Take a large population who are already taking a particular treatment or have an exposure, follow them forward over time, and then compare for outcomes with a similar group that has not been affected by the treatment or exposure.

Observational and not as reliable as randomized controlled studies, since the two groups may differ in ways other than in the variable under study.  

Starts with the exposure and follows patients forward to an outcome.

Randomized, controlled clinical trials

Carefully planned projects that introduce a treatment or exposure to study its effect on patients.

Include methodologies that reduce the potential for bias (randomization and blinding) and allow for comparison between intervention and control groups. 

Is an experiment and can provide sound evidence of cause and effect.  

Randomly assigns exposures and then follows patients forward to an outcome.

Systematic Reviews

Usually focus on a clinical topic and answer a specific question. An extensive literature search is conducted to identify studies with sound methodology. The studies are reviewed, assessed, and the results summarized according to the predetermined criteria of the review question. 

Meta-analysis

Thoroughly examines a number of valid studies on a topic and combines the results using accepted statistical methodology to report the results as if it were one large study. 

The Cochrane Collaboration has done a lot of work in the areas of systematic reviews and meta-analysis.

Research Design

Diagnostic tests

Prognosis

Therapy

Patients’ Preferences

Cross sectional study

Cohort study

RCT

Qualitative research

BMJ 1997;315:1636