Neighbourhood environments and mortality in an elderly cohort: results from the cardiovascular health study

Abstract

Background: It has been postulated that neighbourhood conditions are related to the health of the elderly population but longitudinal studies are rare and confounding by individual level variables remains a possibility. Methods: Data were obtained from the cardiovascular health study, a population based study of adults aged 65 years and older. Census block groups were used as proxies for neighbourhoods. A summary score was used to characterise the neighbourhood socioeconomic environment. Information on personal socioeconomic indicators, cardiovascular disease prevalence, and cardiovascular risk factors was obtained from the baseline examination. Proportional hazards regression and propensity score matching were used to control for individual level variables. Results: Over the eight year follow up there were 1346 deaths among the 5074 participants, of which 43% were attributable to cardiovascular disease. Among white participants, living in the most disadvantaged neighbourhood group was associated with higher rates of cardiovascular death, after adjustment for income, education, and occupation (hazard ratio (HR) 1.5, 95% confidence intervals (CI) 1.2 to 1.9). No neighbourhood differences were observed for non-cardiovascular deaths. Estimates for black participants were 1.3 (95% CI 0.7 to 2.3) for cardiovascular deaths and 1.4 (95% CI 0.8 to 2.4) for non-cardiovascular deaths, but sample size was small. In white participants, associations of neighbourhood characteristics with cardiovascular mortality persisted after adjustment for prevalent baseline disease and cardiovascular risk factors. The use of propensity score matching led to similar results (HR for the lowest compared with the highest neighbourhood score group: 1.6 95% CI 1.1 to 2.5, controlling for personal socioeconomic indicators). Conclusion: Neighbourhood disadvantage is related to rates of cardiovascular death in elderly white adults.