Identification of problems in search strategies in Cochrane Reviews

Search strategies are essential for the adequate retrieval of studies in a systematic review (SR). Our objective was to identify problems in the design and reporting of search strategies in a sample of new Cochrane SRs first published in The Cochrane Library in 2015.

We took a random sample of 70 new Cochrane SRs of interventions published in 2015. We evaluated their design and reporting of search strategies using the recommendations from the Cochrane Handbook for Systematic Reviews of Interventions, the Methodological Expectations of Cochrane Intervention Reviews, and the Peer Review of Electronic Search Strategies evidence-based guideline.

Most reviews complied with the reporting standards in the Cochrane Handbook and the Methodological Expectations of Cochrane Intervention Reviews; however, 8 SRs did not search trials registers, 3 SRs included language restrictions, and there was inconsistent reporting of contact with individuals and searches of the gray literature. We found problems in the design of the search strategies in 73% of reviews (95% CI, 60-84%) and 53% of these contained problems (95% CI, 38-69%) that could limit both the sensitivity and precision of the search strategies.

We found limitations in the design and reporting of search strategies. We consider that a greater adherence to the guidelines could improve their quality.