Objectives: Individuals who feel lonely and those who are socially isolated have higher mortality risks than those who are not lonely or socially isolated. However, the importance of loneliness and social isolation for survival is rarely analysed in the same study or with consideration of gender differences. The aim was to examine the separate, mutually adjusted, and combined effects of loneliness and social isolation with mortality in older women and men.

Methods: Data from the SWEOLD study, a nationally representative sample of people aged 69+ years living in Sweden, was combined with register data on mortality and analysed using Cox regressions.

Results: Mortality was higher among older women and men with higher levels of loneliness or social isolation. Social isolation was more strongly associated with mortality than loneliness and the association remained when controlling for health. The combined effects of loneliness and social isolation did not surpass their independent effects.

Conclusion: Loneliness and social isolation is associated with an increased mortality risk, and social integration should be a prioritised target for activities and services involving older adults.