Individual versus group-based interventions: a systematic review and meta-analysis of physical activity, functional, psychosocial and health outcomes

max). Using a three-level random effects model, group-based conditions showed a small but non-significant advantage for PA (n = 22,042; g = 0.086, 95% CI (-0.061, 0.233), P = 0.249), psychosocial outcomes (n = 18,223; g = 0.292, 95% CI (-0.171, 0.755), P = 0.214) and health outcomes (n = 31,607; g = 0.125, 95% CI (-0.023, 0.272), P = 0.096). For functional outcomes, a significant advantage for group-based interventions emerged after outlier removal (n = 14,429; g = 0.164, 95% CI (0.032, 0.297), P = 0.015). Moderation analysis indicated that different group types produced comparable effects, except that 'true groups' were associated with a larger effect size for health outcomes. Both individual and group-based approaches (in-person or online) may be effective. Future research should explore mechanisms that enhance their impact across populations and settings. This review was prospectively registered with PROSPERO (CRD42021271452).