Evidence Based Medicine (EBM)

Last updated 12.12.12

 

Definition

-  The application of the best & most current available clinical evidence, from systematic research, to decision making in regards to patient care

 

Features

-  Gathered momentum in 1990s

 

Procedure

-  Determine question type

-  Intervention/therapy

-  Diagnosis

-  Aetiology

-  Prognosis

-  Create the clinical question using PICO

-  Population/Disease

-  Intervention (study factor)

-  Comparator

-  Outcome

-  Determine best study type to answer question

-  Intervention/therapy: RCT

-  Diagnosis: Cross-Sectional Analytic

-  Aetiology: Cohort Study or Case Control Study

-  Prognosis: Cohort Study

-  Select most appropriate database/search method

-  Undertake search of literature

-  Critical analysis of research

 

Critical Analysis of Therapeutic Studies

-  Are the results valid?

-  Was the assignment of patients randomised?

-  Was there allocation concealment?

-  Were all patients who entered the trial accounted for and attributed at its conclusion?

-  Were patients, clinicians & study personnel blinded to the treatment?

-  Were the groups similar at the start of the trial?

-  Aside from the experimental intervention were the groups treated equally?

-  What are the results?

-  How large is the treatment effect?

-  How precise is the estimate of the treatment effect?

-  Will the results help me in my patient care?

-  Can the results be applied to my patients?

-  Were all clinically relevant outcomes considered?

-  Are the benefits worth the harms & costs?

-  Relative Risk, Risk Ratio

-  Relative Risk Reduction

-  Absolute Risk Reduction

-  Number Needed to Treat

 

Critical Analysis of Diagnostic Test Studies

-  Are the results valid?

-  Was there an independent, blind comparison with a reference standard?

-  Did the patient sample include an appropriate spectrum of patients to whom the test will be applied?

-  Did the results of the test being evaluated influence the decision to perform the reference standard?

-  Were the tests methods described clearly enough to permit replication?

-  What are the results?

-  What are the likelihood ratios for the test results?

-  Will the results help me in my patient care?

-  Will the test be reproducible and well interpreted in my practice setting?

-  Are the results applicable to my patients?

-  Will the test results change my management?

-  Will my patients be better off because of the test?

-  Likelihood Ratio

-  Pretest Prbabilities

 

Critical Analysis of Systematic Reviews

-  Are the results valid?

-  Did this review address a focused clinical question?

-  Were the criteria for article inclusion appropriate?

-  It is unlikely that relevant studies were missed?

-  Was the validity of the included studies appraised?

-  Was the assessments of studies reproducible?

-  Were the results similar from study to study?

-  What are the results?

-  What are the overall results of the review?

-  How precise are the results?

-  Will the results help me in my patient care?

-  Can the results be applied to my patients?

-  Were all clinically important outcomes considered?

-  Are the benefits worth the harms & costs?

-  Test of Homogeneity

 

Critical Analysis of Studies of Harm

-  Are the results valid?

-  Except for the exposure under study were the compared groups similar to each other?

-  Were the outcomes and exposures measured in the same ways in both groups?

-  Was the follow up of patients sufficiently long & complete?

-  Is the temporal relationship correct?

-  Is there a dose-response gradient?

-  What are the results?

-  How strong is the association between exposure & outcome?

-  How precise is the estimate of risk?

-  Will the results help me in my patient care?

-  Are the results applicable to my patients?

-  What is the magnitude of the risk?

-  Should I attempt to stop the exposure?

 

Critical Analysis of Prognostic Studies

-  Are the results valid?

-  Was a defined representative sample of patients assembled at a similar point in the course of disease?

-  Was a follow-up sufficiently long & complete?

-  Were objective & unbiased outcome criteria used?

-  Was there adjustment for important prognostic factors?

-  What are the results?

-  How likely are the outcomes over time?

-  How precise are the estimates of prognosis?

-  Will the results help me in my patient care?

-  Were the study patients similar to my own?

-  Will the results lead directly to selecting therapy?

-  Are the results useful for counseling patients?

-  P value

-  Confidence Interval

 

 

 

References

 

Sydney University: sydney.edu.au/medicine/public-health/current/research/ebm.php

JAMA 1993; 270 & 271 & 272