Social participation as a modifiable social determinant of health: A systematic review and dose-response meta-analysis of all-cause mortality in older adults.
OBJECTIVE To examine the association between social participation and all-cause mortality among older adults, evaluate associations across different types of social participation, and explore the dose-response relationship between monthly participation frequency and mortality to inform nursing practice and social prescribing strategies. METHODS We systematically searched five electronic databases from inception to April 27, 2025, supplemented by reference list screening. Hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled using random-effects models. Methodological quality was assessed using the Newcastle-Ottawa Scale. Dose-response associations were examined by harmonizing participation frequency into sessions per month. RESULTS This meta-analysis of 25 prospective cohort studies showed that social participation was associated with lower all-cause mortality among older adults. Compared with low participation, high participation was associated with a lower mortality risk (HR = 0.67, 95% CI: 0.58-0.77), and this association remained statistically significant after adjustment (adjusted HR = 0.78, 95% CI: 0.74-0.82). Domain-specific analyses suggested inverse associations across several activities, including religious participation, volunteering, hobby clubs, sports groups, and community engagement, with adjusted HRs ranging from 0.74 to 0.82. An exploratory dose-response analysis suggested a possible inverse association between monthly participation frequency and all-cause mortality; each additional monthly session was associated with a lower relative hazard of mortality (HR = 0.946, 95% CI: 0.935-0.960). CONCLUSION Social participation was associated with lower all-cause mortality among older adults and may inform nursing and public health strategies that promote social engagement in later life. However, these findings should be interpreted cautiously because the evidence was observational, several analyses showed moderate-to-substantial heterogeneity, and the exploratory dose-response analysis was based on only five studies. Future longitudinal studies with standardized exposure assessment and rigorous adjustment for baseline health and functional status are needed.