Best Practices for Meta-Reviews in Physical Activity and Health Research: Insights From the Physical Activity Guidelines for Americans Advisory Committee Scientific Report.

Abstract

Systematic reviews (SRs) and meta-analyses (MAs) have proliferated with a concomitant increase in reviews of SRs/MAs or "meta-reviews" (MRs). As uncovered by the 2018 US Physical Activity Guidelines Advisory Committee (PAGAC), there is a paucity of best practice guidance on MRs on physical activity health-related research. This manuscript aims to fill this gap. In total, the PAGAC conducted 38 literature searches across 3 electronic databases and triaged 20,838 titles, 4913 abstracts, and 2139 full texts from which 1130 articles qualified for the PAGAC Scientific Report. During the MR process, the following challenges were encountered: (1)if the SR/MA authors had limited experience in synthesis methodology, they likely did not account for risk of bias in the conclusions they reached; (2)many SRs/MAs reviewed the same primary-level studies; (3)many SRs/MAs failed to disclose effect modifier analyses; (4)source populations varied; (5)physical activity exposures were nonstandardized; and (6)dose-response effects or effect modification of the physical activity exposure could not be identified. Using examples from the PAGAC Scientific Report, we provide (1)a high-level introduction to MRs; (2)recommended steps in conducting a MR; (3)challenges that can be encountered; and (4)guidance in addressing these challenges.