Meta-analysis of Observational Studies in Epidemiology - A Proposal for Reporting

ObjectiveBecause of the pressure for timely, informed decisions in public healthand clinical practice and the explosion of information in the scientific literature,research results must be synthesized. Meta-analyses are increasingly usedto address this problem, and they often evaluate observational studies. Aworkshop was held in Atlanta, Ga, in April 1997, to examine the reportingof meta-analyses of observational studies and to make recommendations to aidauthors, reviewers, editors, and readers.ParticipantsTwenty-seven participants were selected by a steering committee, basedon expertise in clinical practice, trials, statistics, epidemiology, socialsciences, and biomedical editing. Deliberations of the workshop were opento other interested scientists. Funding for this activity was provided bythe Centers for Disease Control and Prevention.EvidenceWe conducted a systematic review of the published literature on theconduct and reporting of meta-analyses in observational studies using MEDLINE,Educational Research Information Center (ERIC), PsycLIT, and the Current Indexto Statistics. We also examined reference lists of the 32 studies retrievedand contacted experts in the field. Participants were assigned to small-groupdiscussions on the subjects of bias, searching and abstracting, heterogeneity,study categorization, and statistical methods.Consensus ProcessFrom the material presented at the workshop, the authors developed achecklist summarizing recommendations for reporting meta-analyses of observationalstudies. The checklist and supporting evidence were circulated to all conferenceattendees and additional experts. All suggestions for revisions were addressed.ConclusionsThe proposed checklist contains specifications for reporting of meta-analysesof observational studies in epidemiology, including background, search strategy,methods, results, discussion, and conclusion. Use of the checklist shouldimprove the usefulness of meta-analyses for authors, reviewers, editors, readers,and decision makers. An evaluation plan is suggested and research areas areexplored.