Persistence of social isolation and mortality: 10-year follow-up of the Guangzhou Biobank Cohort study

Although social isolation has been associated with higher mortality risk, the associations of persistence of social isolation with mortality are unclear. We investigated the prospective associations of intermittent and persistent social isolation with all-cause and cause-specific mortality, considering the social contact types (face-to-face and non-face-to-face). 30,518 participants were recruited in 2003-2008 initially and 18,104 participants with re-assessed social isolation information in 2008-2012 were followed up to Dec 2019 in Guangzhou Biobank Cohort Study (GBCS). During an average of 9.7 years of follow-up, 2,119 deaths occurred. The isolation at baseline survey, isolation at second survey and persistent isolation were positively associated with all-cause mortality in the minimal adjusted model (adjusted hazard ratio (AHR) =1.24, 95% CI 1.12-1.38, 1.11, 1.00-1.23 and 1.23, 1.05-1.43, respectively). Totally 47.2% of the risk was explained by health status, SEP, and biological, behavioural and psychological factors. Persistent isolation from face-to-face with co-inhabitants, versus no isolation, was associated with higher risks of all-cause (HR=1.40, 1.09-1.81) and CVD (subdistribution hazard ratio (SHR)=1.92, 1.31-2.81) mortality in fully adjusted model. Our study showed that intermittent and persistent isolation were generally associated with higher risks of mortality, and the risks were even higher in those with persistent face-to-face isolation with co-inhabitants.