Abstract

BACKGROUND AND PURPOSE:

Greater social cohesion is related to lower rates of coronary heart disease, but its relation to stroke risk is unstudied. This study examined whether neighborhood social cohesion was protective against stroke mortality and incidence.

METHODS:

Data come from 5789 participants (60% female; 62% black; mean age, 74.7 years) in a longitudinal study of chronic diseases in the elderly. Stroke mortality, ascertained through December 31, 2007, was verified through the National Death Index; 186 stroke deaths were identified in 11 years of follow-up. Stroke incidence was determined in a subset (N=3816) with linkage to Medicare claims files; 701 first-ever strokes were identified. Cohesion was measured by 6 items assessing frequency of contact and social interactions with neighbors; items were z-scored and averaged. Individual scores were averaged across 82 census block groups, forming a neighborhood-level measure of social cohesion. Marginal Cox proportional hazard models tested the association of neighborhood-level cohesion with stroke mortality and incidence.

RESULTS:

Each 1-point increase in cohesion related to a 53% reduced risk of stroke mortality (hazard ratio, 0.47; 95% CI, 0.24 to 0.90), adjusting for relevant covariates, including sociodemographics, known stroke risk factors, and neighborhood-level socioeconomic status. A race×cohesion interaction (P=0.04) revealed cohesion was protective in whites (hazard ratio, 0.34; 95% CI, 0.17 to 0.67) but not blacks (hazard ratio, 1.17; 95% CI, 0.35 to 3.86). Cohesion was unrelated to stroke incidence (P>0.5).

CONCLUSIONS:

Neighborhood-level social cohesion was independently protective against stroke mortality. Research is needed to further examine observed race differences and pathways by which cohesion is health-protective.