Analysis of the reporting of search strategies in Cochrane systematic reviews

Background: The Cochrane Handbook for Systematic Reviews of Interventions provides instructions for documenting a systematic review's electronic database search strategy, listing elements that should be in the description. Complete documentation of the search strategy allows readers to evaluate the search when critically appraising a review's quality. Objective: The research analyzed recently published Cochrane reviews to determine whether instructions for describing electronic database search strategies were being followed. Methods: Eighty-three new reviews added to the Cochrane Database of Systematic Reviews in the first quarter of 2006 were selected for analysis. Eighteen were subsequently excluded because their searches were conducted only in the specialized registers of Cochrane review groups. The remaining sixty-five reviews were analyzed for the seven elements of an electronic database search strategy description listed in the Cochrane Handbook, using dual review with consensus. Results: Of the 65 reviews analyzed, none included all 7 recommended elements. Four reviews (6%) included 6 elements. Thirty-two percent (21/65) included 5 or more elements, with 68% (44/65) including 4 or fewer. Three included only 2 elements. The 65 reviews represented 41 different Cochrane review groups. Conclusion: The instructions from the Cochrane Handbook for reporting search strategies are not being consistently employed