How comprehensive is the Cochrane Central Register of Controlled Trials for identifying clinical trial registration?: the protocol of a diagnostic study

ObjectivesTo evaluate whether or not systematic reviewers can use Cochrane Central Register of Controlled Trials (CENTRAL) to identify ongoing and unpublished studies instead of searching International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov (CT.gov). MethodsThis will be a diagnostic accuracy test study. We will collect a consecutive sample of ongoing or unpublished studies on Cochrane Database of Systematic Reviews (CDSRs) during the last six months. We will use all of the records as our reference standard and evaluated whether they are part of the CENTRAL search presented in the CDSRs. The index test is the CENTRAL search using the search terms in the CDSRs, and the reference standard is the list of ongoing or unpublished studies registered on the ICTRP or CT.gov in the CDSRs. We will assess the sensitivity and number needed to read. Ethics & DisseminationThis study does not require ethics approval. We registered this study protocol. We will publish the findings in a peer-reviewed journal and may present them at conferences. DiscussionThis study may lessen the burden of systematic reviewers if this study clarifies CENTRAL search can be used for screening in records about ongoing or unpublished studies. RegistrationUMIN-CTR: UMIN000038981 Author name abbreviationsMasahiro Banno (MB), Yasushi Tsujimoto (YT), Yuki Kataoka (YK)