ObjectiveTo investigate the status of research and development methods of Cochrane overviews.
MethodsThe Cochrane Library and PubMed were searched up to March 2014 to identify Cochrane overviews. According to the inclusion and exclusion criteria, two reviewers independently screened literature, extracted data, and assessed and analyzed search strategy, quality assessment method, data analysis, and study results.
ResultsA total of 18 Cochrane overviews were included. Among them, 4 (22.2%) overviews included formal statistical indirect comparison; 8 (44.4%) included only results from direct comparison; 6 (33.4%) only systematically analyzed current studies without data pooling; 12 (66.7%) only searched The Cochrane Library, while 6 (33.3%) expanded search to other databases; 14 (77.8%) applied the AMSTAR tool to assess methodological quality of included literature; 12 (66.7%) applied the GRADE system to assess the quality of evidence; and 9 (50%) yielded new outcomes.
ConclusionCurrently, the development and reporting standards of Cochrane overviews are still immature. Investigators should choose proper methods based on research objectives when developing Cochrane overviews.
