Background: Trial registry records and published randomized controlled trial (RCT) study protocols can facilitate transparency in the conduct and reporting of clinical trials. Registry records and RCT study protocols can be employed in systematic reviews to minimize bias and assist in planning for updates. Searching trial registries is mandatory for Cochrane Systematic Reviews, but guidance on the utilization of RCT study protocols and trial registry records is limited.
Objectives: To describe how trial registry records and/or published RCT protocols are currently utilized in Cochrane Systematic Reviews of interventions.
Methods: We will search the Cochrane Database of Systematic Reviews for systematic reviews of interventions published within the past year. Only systematic reviews of RCTs examining the efficacy of an intervention will be included. Systematic review protocols, overview of reviews, and systematic reviews of non-randomized trials, diagnostic, prognostic or methods will be excluded. A stratified random sample (using a 95% confidence level to establish sample size) of the identified reviews will be selected for screening. Articles will be reviewed for inclusion by two independent reviewers and disagreements will be resolved by consensus. A content analysis will guide the text analysis. NVivo software will be employed for the analysis (e.g. count usages of RCT study protocols, trial registry records and related terms). The terms’ location(s) within the systematic review (e.g. in the search methods) and textual excerpts will be documented for descriptive analysis. Results will be compared across Editorial Review Groups.
Results: A total of 835 systematic reviews of interventions published in the past year were identified, with the highest number from the Pregnancy and Childbirth Group and none from the Urology Group. Further results are expected by the summer of 2016.
Conclusions: The results of this review will inform the reader about current practices for utilizing registry records and protocols in systematic reviews, as well as identifying methodological gaps.