Abstract
BACKGROUND: We investigated the association of living alone with mortality among older persons, independently of marital, health and other factors, and explored its effect modification by age group, sex, marital status and physical functional disability. METHOD: Using data from 8 years of mortality follow up (1 September 2003 to 31 December 2011) of 2553 participants in the Singapore Longitudinal Ageing Studies (SLAS) cohort, we estimated hazard ratio (HR) of mortality associated with living alone using Cox proportional hazard models. RESULTS: At baseline, 7.4 % (N = 189) of the participants were living alone, and 227 (8.9 %) died during the follow up period. Living alone was significantly associated with mortality 1.66 (95 % CI, 1.05-2.63), controlling for health status (hypertension, diabetes, chronic lung disease, stroke, heart disease, kidney failure, IADL-ADL disability and depressive symptoms), marital status and other variables (age, sex, housing type). Possible substantive effect modification by sex (p for interaction = 0.106) and marital status (p for interaction <0.115) were observed: higher among men (HR = 2.36, 95 % CI, 1.24-4.49) than women (HR = 1.14, 95 % CI, 0.58-2.22), and among single, divorce or widowed (HR = 2.26, 95 % CI, 1.24-4.10) than married individuals (HR = 0.83, 95 % CI, 0.30-2.31). CONCLUSION: Living alone was associated with increased mortality, independently of marital, health and other variables. The impact of living alone on mortality appeared to be stronger among men and those who were single, divorced or married.