Association of community level social trust and reciprocity with mortality: a retrospective cohort study.

Background: Whether community level social capital is associated with mortality within an Asian population is yet unclear.
Methods: The study population was derived from the Korean National Health Insurance Service-National Sample Cohort. A total of 636,055 participants were followed-up during 2012-2013 for deaths from all causes, cardiovascular disease (CVD), cancer, and other causes. Community level social trust and reciprocity at the administrative district level were derived from the Korean Community Health Survey. Cox proportional hazards regression was used to determine the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for mortality according to levels of community level social trust and reciprocity.
Results: Compared to participants who reside in areas within the lower half of community level social trust, those who reside in areas within the upper half had lower risk of death from all causes (aHR 0.84, 95% CI 0.78-0.89), CVD (aHR 0.82, 95% CI 0.67-0.99), and cancer (aHR 0.85, 95% CI 0.73-0.98). Similarly, residing in areas in the upper half of community level social reciprocity was associated with reduced risk for all-cause mortality (aHR 0.80, 95% CI 0.75-0.86). The protective association of high community level social trust and reciprocity on mortality remained after additional adjustments for smoking, alcohol intake, and physical activity.
Conclusions: Residing in areas with high community level social trust and reciprocity may be associated with better population health status.