Strategies used to manage overlap of primary study data by exercise-related overviews. Protocol for a systematic methodological review

Abstract

AbstractIntroductionOne of the most conflicting methodological issues when conducting an overview is the overlap of primary studies included across systematic reviews (SRs). Overlap in the pooled effect estimates across SRs may lead to overly precise effect estimates in the overview. SRs that focus on exercise-related interventions are often included in overviews aimed at grouping and determining the effectiveness of various interventions for the management of specific health conditions.ObjectiveThe aim of this systematic methodological review is to describe the strategies used by authors of overviews focusing on exercise-related interventions to manage the overlap of primary studies.Materials and methodsA comprehensive search strategy has been developed for different databases and their platforms. The databases to be consulted will be MEDLINE (Ovid), Embase (Ovid), The Cochrane Database of Systematic Reviews (Cochrane Library), and Epistemonikos. Two reviewers will independently screen the records identified through the search strategy and will extract the information from the included overviews. The frequency and the type of overlap management strategies of the primary studies included in the SRs will be considered as the main outcome. In addition, the recognition of the lack of use of any overlap management strategy and the congruence between planning and conducting the overview focusing on overlap management strategies will be assessed. A sub-group analysis will be carried out using the impact factor of the journals at the time of publication of the overviews as the variable.DiscussionThis methodological review will provide a complete and comprehensive summary of the frequency of use and types of strategies used for managing the overlap of primary studies across the SRs included in the overviews focusing on exercise-related interventions in different health conditions. Future studies should apply different overlap management strategies to understand their impact on results and conclusions.Systematic review registrationINPLASY202250161.