A Scoping Review of Published and Ongoing Prospective Meta-Analyses in Health Research: Study Protocol

BackgroundProspective meta-analysis (PMA) is an emerging evidence synthesis methodology, in which the study selection criteria, hypotheses and analyses are finalised prior to the knowledge of included study results. This has numerous benefits over retrospective meta-analysis, including a reduction in selection bias, selective outcome reporting and publication bias and improved data harmonisation. Yet, common misunderstandings of the PMA methodology remain, leading to inappropriate and/or suboptimal implementation by researchers. ObjectivesTo investigate the landscape of the published and ongoing prospective meta-analyses. MethodsWe will systematically search the International prospective Register of Systematic Reviews (PROSPERO) for PMAs from inception to January 2023 and screen these studies in COVIDENCE. The results of this search will be combined with a search of medical databases (PubMed, Embase, Cochrane Database of Systematic Reviews) up to 2018, to capture PMA that started prior to the launch and subsequently increasingly wide implementation of PROSPERO in February 2011. All PMAs conducted in human health research will be eligible for inclusion. All records will be double-screened, and data will be double extracted, with conflicts resolved through consensus. DisseminationInsights from this scoping review will inform adaptions to current PMA guidelines and thus assist researchers in planning future PMAs in their fields.