Review Question - QID 4460

A systematic review of high-quality clinical trials is considered a Level I study.

A systematic review is a powerful tool used to identify, evaluate and appraise all high-quality research related to a specific question. Systematic reviews, in contrast to most narrative review articles, adhere to strict scientific design by following eight steps; 1) defining a question and developing inclusion criteria, 2) searching for studies, 3) selecting studies and collecting data, 4) assessing risk of bias, 5) data analysis and meta-analyses, 6) addressing biases, 7) presenting results, and 8) interpreting results and drawing conclusions. When the results from the systematic review are homogeneous (less variability between studies than would be expected by chance), the data from a systematic review can be combined into a meta-analysis.

Wright et al. discuss the levels of evidence in orthopaedic journals as presented by the AAOS Evidence-Based Practice Committee. Based on levels of evidence, the AAOS provides grades of recommendation (A, B, C, I). Grade A recommendations are supported by Level 1 studies with consistent findings, whereas Grade I do not have enough evidence to support a recommendation.

Illustration A shows an "evidence pyramid." MA = meta-analysis, SR = systematic review, RCT = randomized controlled trial.

Incorrect Answers:
Answer 2: An example of a Level II study is prospective comparative study.
Answer 3: An example of a Level III study is a case control trial.
Answer 4: An example of a Level IV study is a case series.
Answer 5: An example of a Level V study is one based on expert opinion.