Impact of living alone on institutionalization and mortality: a population-based longitudinal study

Background: Living alone is common among elderly people in Western countries, and studies on its relationship with institutionalization and all-cause mortality have shown inconsistent results. We investigated that the impact of living alone on institutionalization and mortality in a population-based cohort of elderly people. Methods: Data originate from the Swedish National study on Aging and Care-Kungsholmen. Participants aged >= 66 years and living at home (n = 2404) at baseline underwent interviews and clinical examination. Data on living arrangements were collected in interviews. All participants were followed for 6 years; survival status and admission into institutions were tracked continuously through administrative registers from 2001 to 2007. Data were analysed using Cox proportional hazard models, competing risk regressions and Laplace regressions with adjustment for potential confounders. Results: Of the 2404 participants, 1464 (60.9%) lived alone at baseline. During the follow-up, 711 (29.6%) participants died, and 185 (15.0%) were institutionalized. In the multi-adjusted Cox model, the hazard ratio (HR) of mortality in those living alone was 1.35 (95% confidence interval [CI] 1.18 to 1.54), especially among men (HR = 1.44, 95% CI 1.18 to 1.76). Living alone shortened survival by 0.6 years and was associated with the risk of institutionalization (HR = 1.74, 95% CI 1.10 to 2.77) after taking death into account as a competing risk. Conclusions: Living alone is associated with elevated mortality, especially among men and an increased risk of institutionalization. Over a 6-year period, living alone was related to a half year reduction in survival among elderly people in Sweden.