Studies on the relation between service attendance and mortality often have been limited by inadequate methodology for reverse causation, inability to assess effects over time, and limited information on mediators and cause-specific mortality.
We evaluated associations between attendance and mortality in a prospective cohort, the Nurses’ Health Study (NHS), which included 74,534 women who were free of cardiovascular disease (CVD) and cancer at baseline. Religious service attendance was assessed by a self-reported question and was collected in 1992 and every four years subsequently. We used Cox proportional hazard model and marginal structural models with time-varying covariates to examine the association of religious service attendance with all-cause and cause-specific mortality. We adjusted for a wide range of demographic covariates, lifestyle factors and medical history measured repeatedly during the follow-up, and performed sensitivity analyses to examine the influence of potential unmeasured and residual confounding.
During follow-up from 1996 until 2012, we identified 13,537 deaths, including 2,721 due to cardiovascular diseases and 4,479 due to cancer. After multivariate adjustment for major lifestyle, risk factors and attendance in 1992, attending religious service more than once/week was associated with 33% lower all-cause mortality, compared with women who had never attended religious services (Hazard Ratio [HR]=0.67, 95% confidence interval [CI]: 0.62–0.71, p for trend <0.0001). Comparing women who attended religious services more than once per week with those who never attend, the HR for cardiovascular mortality was 0.73 (0.62–0.85, p for trend <0.0001); and cancer mortality was 0.79 (0.70–0.89, p for trend <0.0001). Results were robust in sensitivity analysis. We found evidence that social support, depressive symptoms, smoking and optimism mediated the relationship between attendance and mortality.