The association between social fragmentation and deaths attributable to alcohol, drug use, and suicide: Longitudinal evidence from a population-based sample of Canadian adults

Background: Social fragmentation has been theorized and empirically associated with suicide in prior research. However, less is known about whether social fragmentation is associated with deaths attributed to alcohol use or drug use. This research examined the association between social  fragmentation and risk for deaths attributable to alcohol use, drug use, and suicide (collectively known as deaths of despair) among Canadian adults. Methods: A weighted sample representing 15,324,645 Canadians within 288 census divisions between 2006 and 2019 was used. Mortality data from the Canadian Vital Statistics Database (alcoholic liver disease, drug use, and suicide) was linked with census division socioeconomic data from  the 2006 Canadian census using the Canadian Census Health and Environment Cohorts. Social fragmentation at the census division was created based on the Congdon Index. Cox-proportional hazard regression with survey weights and the sandwich estimator were used to account for clustering of individuals (level-1) nested within census divisions (level-2).+ Results: After adjusting for individual and census division confounders, social fragmentation was positively associated with all-cause mortality (HR = 1.04; 95% CI: 1.02, 1.07), suicide (HR = 1.09; 95%CI: 1.01, 1.18), drug overdose related mortality (HR = 1.13; 95%CI: 1.03, 1.24), and deaths of  despair (HR = 1.10; 95% CI: 1.04, 1.16), and not significantly associated with alcohol related liver disease (HR = 1.06; 95% CI: 0.91, 1.23). Conclusion: Social fragmentation is associated with an increased hazard of deaths of despair among Canadian adults. Efforts to improve social cohesion in areas that are highly socially fragmented need to be evaluated.