Living alone is associated with all-cause and cardiovascular mortality: 32 years of follow-up in the Copenhagen Male Study

AIMS: As a consequence of modern urban life, an increasing number of individuals are living alone. Living alone may have potential adverse health implications. The long-term relationship between living alone and all-cause and cardiovascular mortality, however, remains unclear. METHODS AND RESULTS: Participants from The Copenhagen Male Study were included in 1985-86 and information about conventional behavioural, psychosocial, and environmental risk factors were collected. Socioeconomic position (SEP) was categorized into four groups. Multivariable Cox-regression models were performed with follow-up through the Danish National Registries. A total of 3346 men were included, mean (standard deviation) age 62.9 (5.2) years. During 32.2 years of follow-up, 89.4% of the population died and 38.9% of cardiovascular causes. Living alone (9.6%) was a significant predictor of mortality. Multivariable risk estimates were hazard ratio (95% confidence interval) 1.23 (1.09-1.39), P = 0.001 for all-cause mortality and 1.36 (1.13-1.63), P = 0.001 for cardiovascular mortality. Mortality risk was modified by SEP. Thus, there was no association in the highest SEP but for all other SEP categories, e.g. highest SEP for all-cause mortality 1.01 (0.7-1.39), P = 0.91 and 0.94 (0.6-1.56), P = 0.80 for cardiovascular mortality; lowest SEP 1.58 (1.16-2.19), P = 0.004 for all-cause mortality and 1.87 (1.20-2.90), P = 0.005 for cardiovascular mortality. Excluding participants dying within 5 years of inclusion (n = 274) did not change estimates, suggesting a minimal influence of reverse causation. CONCLUSIONS: Living alone was an independent risk factor for all-cause and cardiovascular mortality with more than three decades of follow-up. Individuals in middle- and lower SEPs were at particular risk. Health policy initiatives should target these high-risk individuals.