5S Hierarchy of EvidenceHaynes RB. Evid Based Med 2006;11:162-164 Computerized decision support system Evidence-Based Guidelines & Textbooks Secondary Critically-Appraised Journal Articles & Abstracts Systematic Reviews RCTs, Cohort, Case control, Case series Primary Expert Opinion: Classical Textbooks
Searching for evidence Case report, Case series, Case-Control, Cohort, Randomized Trial DiCenso A, Bayley L, Haynes RB. Accessing preappraised evidence: fine-tuning the 5S model into a 6S model. ACP Journal Club, 2009
Tough Job If you have to do the critical appraisal for every single article you read Tough BUT You need to learn about it in details for the sake of research
Don’t say there is “no evidence” Instead Weak evidence You might not have looked thorough enough
Absence of evidence is not the evidence of absence
Satisficing ‘‘where busy clinicians will be satisfied with the information they can readily summon, while sacrificing quality for convenience” Carter BS, Leuthner S. Decision making in the NICU—strategies, statistics and ‘‘satisficing.’’ Bioethics Forum. 2002;18:7–15.
Usefulness of information Hurwitz SR, Slawson DA, Shaughnessy A. Orthopaedic information mastery: applying evidence-based information tools to improve patient outcome while saving orthopaedists’ time. J Bone Joint Surg Am. 2000;82:888–895.
Syntheses The authors have done the work for you Hopefully: They asked a good question They searched the literature systematically (keywords & MeSH) They identified the studies and assessed their quality This is called Systematic Review If they did statistical combination of results, this is called Meta-analysis
How to search for “Syntheses”? Same databases: MEDLINE, EMBASE Cochrane Library
Synopses Physicians with training in research methodology: Read the articles Assess their quality Summarize them for you Many sources: Database of Abstracts of Reviews of Effects (DARE) ACP Journal Club Evidence-based sections in many journals Others: DynaMed, EvidenceMatters, EssentialEvidence