A review identified challenges distinguishing primary reports of randomized trials for meta-research: A proposal for improved reporting

Meta-research is the discipline of studying research itself. A core investigative tool in meta-research is the use of systematic or scoping reviews to study the characteristics, methods and reporting of primary research studies. In the context of identifying eligible publications for methodological reviews of randomized controlled trials (RCTs), a challenge is to efficiently distinguish the primary trial report — which reports results for the primary outcome — from other types of reports, including design papers and secondary or supplementary analyses, or what we collectively refer to as non-primary reports. This may not be a straightforward task and may contribute to inefficiencies in the review process.