Guidance for reporting clinical trial registry records and published protocols use in systematic reviews of interventions

Abstract

Background: Transparency is a tenet of systematic reviews. Searching for clinical trial registry records and published protocols has become a mandatory standard when conducting a systematic review of interventions. However, there is no comprehensive guidance for review authors on how to report the use of registry records and published protocols in their systematic review. The objective of this study was to generate initial guidance to assist authors of systematic reviews of interventions in the reporting of registry records and published protocols in systematic reviews of interventions. Methods: We used a compilation of the procedures recommended by expert organizations (e.g., Cochrane Collaboration) related to the reporting of use of registry records and published protocols in the conduct of systematic reviews. The compilation was developed by one of the authors in this study and served as a starting point in developing the algorithm. We extracted current practice data related to registry records and published protocols from a stratified random sample of Cochrane systematic reviews of interventions published between 2015 and 2016 (n=169). We identified examples that adhered to or extended the current guidance. Based on the on the elements above, we created the algorithm to bridge gaps and improve current reporting practices. Results: Trial protocols should be used to account for all evidence in a subject area, evaluate reporting bias (i.e. selective reporting and publication bias), and determine the nature and number of ongoing or unpublished studies for planning review updates. Review authors’ terminology (e.g., ongoing, terminated) and consequent reporting in the review should reflect the phase of the trial found. Protocols should be clearly and consistently reported throughout the review (e.g. abstract, methods, results) as is done with published articles. Conclusions: Our study expands on available guidance to describe in greater detail the reporting of registry records and published protocols for review authors. We believe this is a timely investigation that will increase transparency in the reporting of trial records in systematic reviews of interventions and bring clarification to current fuzziness in terminology. We invite researchers to provide feedback on our work for its improvement and dissemination. Trial Registration: not applicable