Workplace social capital and all-cause mortality: A prospective cohort study of 28043 public-sector employees in Finland

Objectives: We examined the association between workplace social capital and all-cause mortality in a large occupational cohort from Finland. Methods: We linked responses of 28043 participants to surveys in 2000 to 2002 and in 2004 to national mortality registers through 2009. We used repeated measurements of self- and coworker-assessed social capital. We carried out Cox proportional hazard and fixed-effects logistic regressions. Results: During the 5-year follow-up, 196 employees died. A 1-unit increase in the mean of repeat measurements of self-assessed workplace social capital (range 1-5) was associated with a 19% decrease in the risk of all-cause mortality (age- and gender-adjusted hazard ratio [HR]=0.81; 95% confidence interval [CI]=0.66, 0.99). The corresponding point estimate for the mean of coworker-assessed social capital was similar, although the association was less precisely estimated (age- and gender-adjusted HR=0.77; 95% CI=0.50, 1.20). In fixed-effects analysis, a 1-unit increase in self-assessed social capital across the 2 time points was associated with a lower mortality risk (odds ratio=0.81; 95% CI=0.55, 1.19). Conclusions: Workplace social capital appears to be associated with lowered mortality in the working-aged population.