Systematic reviews are structured reviews that use scientific strategies to
reduce bias in the collection, appraisal, and interpretation of relevant s
tudies. We undertook a systematic review of published systematic reviews in
perioperative medicine to summarize the areas currently covered by this ty
pe of literature, to evaluate the quality of systematic reviews in this hel
d and to assess some of the methodologic and reporting issues that are uniq
ue to systematic reviews. Computerized bibliographic databases, citation re
view, and hand searches were performed to identify eligible articles. Quali
ty was assessed using the Overview Quality Assessment Questionnaire. Eight-
two systematic reviews were found. Reviews in perioperative medicine tended
to evaluate prophylactic or therapeutic interventions. No differences were
seen in quality between reviews published in anesthesia and nonanesthesia
journals. Nearly half of all systematic reviews had only minor or minimal f
laws; however, methods can be improved with expanded search strategies, use
of least two reviewers to assess each study, use of validated methods to e
valuate quality, and assessment of potential sources of bias.