Meta-analysis of observational studies in epidemiology - A proposal for reporting

Objective Because of the pressure for timely, informed decisions in public health and clinical practice and the explosion of information in the scient ific literature, research results must be synthesized. Meta-analyses are in creasingly used to address this problem, and they often evaluate observatio nal studies. A workshop was held in Atlanta, Ga, in April 1997, to examine the reporting of meta-analyses of observational studies and to make recomme ndations to aid authors, reviewers, editors, and readers. Participants Twenty-seven participants were selected by a steering committe e, based on expertise in clinical practice, trials, statistics, epidemiolog y, social sciences, and biomedical editing. Deliberations of the workshop w ere open to other interested scientists. Funding for this activity was prov ided by the Centers for Disease Control and Prevention. Evidence We conducted a systematic review of the published literature on th e conduct and reporting of meta-analyses in observational studies using MED LINE, Educational Research Information Center (ERIC), PsycLIT, and the Curr ent Index to Statistics. We also examined reference lists of the 32 studies retrieved and contacted experts in the field. Participants were assigned t o small-group discussions on the subjects of bias, searching and abstractin g, heterogeneity, study categorization, and statistical methods. Consensus Process From the material presented at the workshop, the authors developed a checklist summarizing recommendations for reporting meta-analys es of observational studies. The checklist and supporting evidence were cir culated to all conference attendees and additional experts. All suggestions for revisions were addressed. Conclusions The proposed checklist contains specifications for reporting of meta-analyses of observational studies in epidemiology, including backgrou nd, search strategy, methods, results, discussion, and conclusion. Use of t he checklist should improve the usefulness of meta-analyses for authors, re viewers, editors, readers, and decision makers. An evaluation plan is sugge sted and research areas are explored.