Reproducibility of Search Strategies Is Poor in Systematic Reviews Published in High-Impact Pediatrics, Cardiology and Surgery Journals: A Cross-Sectional Study

Background: A high-quality search strategy is considered an essential component of systematic reviews but many do not contain reproducible search strategies. It is unclear if low reproducibility spans medical disciplines, is affected by librarian/search specialist involvement or has improved with increased awareness of reporting guidelines. Objectives: To examine the reporting of search strategies in systematic reviews published in Pediatrics, Surgery or Cardiology journals in 2012 and determine rates and predictors of including a reproducible search strategy. Methods: We identified all systematic reviews published in 2012 in the ten highest impact factor journals in Pediatrics, Surgery and Cardiology. Each search strategy was coded to indicate what elements were reported and whether the overall search was reproducible. Reporting and reproducibility rates were compared across disciplines and we measured the influence of librarian/search specialist involvement, discipline or endorsement of a reporting guideline on search reproducibility. Results: 272 articles from 25 journals were included. Reporting of search elements ranged widely from 91% of articles naming search terms to 33% providing a full search strategy and 22% indicating the date the search was executed. Only 22% of articles provided at least one reproducible search strategy and 13% provided a reproducible strategy for all databases searched in the article. Librarians or search specialists were reported as involved in 17% of articles. There were strong disciplinary differences on the reporting of search elements. In the multivariable analysis, only discipline (Pediatrics) was a significant predictor of the inclusion of a reproducible search strategy. Conclusions: Despite recommendations to report full, reproducible search strategies, many articles still do not. In addition, authors often report a single strategy as covering all databases searched, further decreasing reproducibility. Further research is needed to determine how disciplinary culture may encourage reproducibility and the role that journal editors and peer reviewers could play.