Introduction A method utilized in the 3rd step of evidence based medicine (EBM) to determine the clinical value of a study five steps of EBM formulate an answerable question gather the evidence appraise the evidence implement the evidence evaluate the process See details of Clinical Design Trials Different Levels of Evidence Level 1 Randomized controlled trial (RCT) a study in which patients are randomly assigned to the treatment or control group and are followed prospectively Meta-analysis of randomized trials with homogeneous results Level 2 Poorly designed RCT follow up less than 80% Prospective cohort study (therapeutic) a study in which patient groups are separated non-randomly by exposure or treatment, with exposure occurring after the initiation of the study Meta-analysis of Level 2 studies Level 3 Retrospective cohort study a study in which patient groups are separated non-randomly by exposure or treatment, with exposure occurring before the initiation of the study Case-control study a study in which patient groups are separated by the current presence or absence of disease and examined for the prior exposure of interest Meta-analysis of Level 3 studies Level 4 Case series a report of multiple patients with the same treatment, but no control group or comparison group Level 5 Case report (a report of a single case) Expert opinion Personal observation JBJS LOE AAOS Recommendations AAOS Evidence-Based Practice Committee Recommendations in Clinical Practice Guidelines Strong • Two or more HIGH quality studies Moderate • One HIGH or 2 MODERATE quality studies Weak • One MODERATE or 1 or more LOW quality studies Consensus • Expert opinion (no studies)* Only used in one circumstance: It pertains to medical interventions that potentially prevent loss of life or limb (catastrophic consequences).
QUESTIONS 1 of 11 1 2 3 4 5 6 7 8 9 10 11 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ13.33) A physician is interested in using platelet-rich plasma (PRP) for treatment of osteochondral lesions of the talus. He is reviewing a prospective cohort study that compares 40 patients treated with PRP and cast immobilization for 6 weeks vs. 36 patients treated conservatively with cast immobilization for 6 weeks. All patients were treated at the same time and institution. The study was not randomized although treatment and control groups were matched appropriately to reduce selection bias. Follow-up in each group was >80% over 1 year. The paper reported significant improvement with use of PRP based on three standard foot and ankle outcome scores (AOFAS, SF-36, FOAS). What is the level of evidence for this study? Review Topic QID: 4668 1 Level I 3% (110/4214) 2 Level II 70% (2964/4214) 3 Level III 23% (978/4214) 4 Level IV 3% (124/4214) 5 Level V 0% (10/4214) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 2 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ12.188) An orthopaedic resident wants to answer a focused research question of whether mobile bearing knee arthroplasty has superior functional outcomes compared to fixed bearing knee arthroplasty. The resident mathematically combines the results from multiple retrospective cohort studies following QUORUM (Quality of Reporting of Meta-analyses) guidelines. What is the highest level of evidence that this meta-analysis can achieve? Review Topic QID: 4548 1 Level I 7% (321/4302) 2 Level II 23% (981/4302) 3 Level III 58% (2481/4302) 4 Level IV 10% (445/4302) 5 Level V 1% (40/4302) ML 4 Select Answer to see Preferred Response PREFERRED RESPONSE 3 (OBQ12.100) A therapeutic study presents a systematic review of 15 high-quality randomized controlled trials with homogeneous results. What level of evidence is this considered? Review Topic QID: 4460 1 I 70% (2656/3769) 2 II 14% (540/3769) 3 III 9% (336/3769) 4 IV 4% (157/3769) 5 V 1% (51/3769) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 1 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ11.239) In the study by Moseley et al published in the New England Journal of Medicine, 180 patients with knee osteoarthritis were randomly assigned via sealed envelope to receive arthroscopic débridement, arthroscopic lavage, or placebo surgery. Outcomes were assessed by blinded evaluators at several points over a 2 year period with the use of five self-reported pain and function scores. There was a greater than 90% follow-up in the study. This study is best described as having which level of evidence? Review Topic QID: 3662 1 Therapeutic study, evidence level I 86% (1066/1243) 2 Therapeutic study, evidence level II 7% (91/1243) 3 Diagnostic study, evidence level I 2% (21/1243) 4 Diagnostic study, evidence level II 1% (8/1243) 5 Prognostic study, evidence level I 4% (49/1243) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 1 (OBQ10.242) Which of the following study designs represent a level III evidence study? Review Topic QID: 3341 1 Prospective, randomized controlled trial 1% (18/1584) 2 Retrospective case-control study 73% (1164/1584) 3 Retrospective case series 17% (262/1584) 4 Prospective cohort study 7% (116/1584) 5 Expert opinion 1% (17/1584) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (OBQ08.127) Using levels of evidence in research studies, which of the following represents a level II study? Review Topic QID: 513 1 Retrospective case control study 9% (137/1534) 2 Prospective cohort study 84% (1283/1534) 3 Case report of 3 patients with the same disease 1% (9/1534) 4 High-quality randomized prospective clinical trial 6% (96/1534) 5 The opinion of a review panel at the annual AAOS meeting 0% (5/1534) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 2