Fig. 1

Decision tool to help researchers make inclusion decisions in overviews. ^aFor detailed instructions on assessing primary study overlap, see Pieper et al. [5]; ^bResearchers should clearly operationalize the criteria they use to define “most recent” and “highest quality.” ^cFor groups of overlapping SRs, researchers may choose to include the most relevant SRs or the most comprehensive SRs (though these inclusion decisions were not examined in this methods study)