comparison of the effectiveness of physical activity and sedentary behaviour interventions in reducing sedentary time in adults: a systematic review and meta‐analysis of controlled trials

The objective of this study was to systematically review the literature and compare the effectiveness of controlled interventions with a focus on physical activity (PA) and/or sedentary behaviours (SBs) for reducing sedentary time in adults. Six electronic databases were searched to identify all studies that examined the effects of interventions that targeted PA and/or SBs and that reported on changes in SBs (sedentary, sitting or television time). A qualitative synthesis was performed for all studies, and meta‐analyses conducted among studies with mean differences (min/d) of sedentary time. PROSPERO: CRD42014006535. Sixty‐five controlled studies met inclusion criteria; 33 were used in the meta‐analyses. Interventions with a focus on PA or that included a PA and SB component produced less consistent findings and generally resulted in modest reductions in sedentary time (PA: standardized mean differences [SMD] = −0.22 [95% confidence interval {CI}: −0.35, −0.10], PA + SB: SMD = −0.37 [95% CI: −0.69, −0.05]). Moderate quality evidence from the randomized controlled trial meta‐analysis coupled with the qualitative synthesis provides consistent evidence that large and clinically meaningful reductions in sedentary time can be expected from interventions with a focus on reducing SBs (SMD = −1.28 [95% CI: −1.68, −0.87] ). There is evidence to support the need for interventions to include a component focused on reducing SBs in order to generate clinically meaningful reductions in sedentary time.