The effects of graded tasks on physical activity: a systematic review and meta-analysis.

This review establishes the extent to which the behaviour change technique (BCT) Graded Tasks is effective in increasing physical activity. Databases, including PubMed, Cochrane and PsycINFO, were searched (October 2024) for randomised control trials of Graded Tasks interventions with adult physical activity change as the main outcome. Graded Tasks were always delivered alongside BCTs 'goal setting (behaviour)' and 'action planning'. Of the 53 identified studies (N = 10,060), 39 were included in a random effects meta-analysis, indicating a significant, medium effect of Graded Tasks interventions in increasing physical activity (N = 4190, g = 0.61, CI 95% 0.42-0.81, p < .001, I2 =  83%). Prevention-based interventions (g = 0.78, CI 95% 0.43-1.12, p < .001, I2 = 90%) had larger effects than treatment-based interventions (g = 0.38, CI 95% 0.23-0.53, p < .001, I2 = 34). The number of Graded Task increments explained significant variability in physical activity change (R2 = 0.47, β = 0.68, p < .001). GRADE certainty of evidence was rated low. Graded Tasks, in conjunction with other BCTs, are effective for increasing physical activity, particularly for prevention. The included studies did, however, show high heterogeneity and potential publication bias. PROSPERO registration: CRD42022347300.