title: Primer on systematic review and meta-analysis.
abstract: A systematic review uses an explicitly defined process to comprehensively identify all studies pertaining to a specific focused question, appraise the methods of the studies, summarize the results, identify reasons for different findings across studies, and cite limitations of current knowledge. Meta-analyses usually combine aggregate-level data reported in each primary study, which may provide a more precise estimate of the "true effect" than any individual study. However, the conclusions may be limited by between-trial heterogeneity, publication bias, or deficits in the conduct or reporting of individual primary studies.
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, Canada.
authors.forename: Marcello
authors.initials: M
authors.lastname: Tonelli
authors.forename: Dan
authors.initials: D
authors.lastname: Hackam
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
mesh_terms: D002986:Clinical Trials as Topic; D019317:Evidence-Based Medicine; D006801:Humans; D015201:Meta-Analysis as Topic; D012107:Research Design; D012196:Review Literature as Topic