The search and selection for primary studies in systematic reviews published in dental journals indexed in MEDLINE was not fully reproducible

Objectives: To evaluate whether the reporting of search strategies and the primary study selection process in dental systematic reviews is reproducible.

Study design and setting: A survey of systematic reviews published in MEDLINE-indexed dental journals from June 2015 to June 2016 was conducted. Study selection was performed independently by two authors, and the reproducibility of the selection process was assessed using a tool consisting of 12 criteria. Regression analyses were implemented to evaluate any associations between degrees of reporting (measured by the number of items positively answered) and journal impact factor (IF), presence of meta-analysis, and number of citations of the systematic review in Google Scholar.

Results: Five hundred and thirty systematic reviews were identified. Following our 12 criteria, none of the systematic reviews had complete reporting of the search strategies and selection process. Eight (1.5%) systematic reviews reported the list of excluded articles (with reasons for exclusion) after title and abstract assessment. Systematic reviews with more positive answers to the criteria were significantly associated with higher journal IF, number of citations, and inclusion of meta-analysis.

Conclusion: Search strategies and primary study selection process in systematic reviews published in MEDLINE-indexed dental journals may not be fully reproducible.