Social isolation, social activity and loneliness as survival indicators in old age; a nationwide survey with a 7-year follow-up

Background: Social networks have been established as a powerful predictors of mortality. However, less is known in how its conceptual dimensions - social isolation, social activity and perceived loneliness are interrelated and to what extent they are independent risk indicators. Objective: To investigate the value of social isolation, social inactivity and loneliness as survival predictors in old age. Method: A postal questionnaire responded by 3858 random older people (> 75 years) included detailed information on social contacts, social activities and loneliness. The vital status was followed for 7 years. Results: Social isolation (46.1%), social inactivity (39.4%), and suffering from loneliness (37.0%) represented population groups of almost equal size, while 23% of people were outside these groups. These groups only partly overlapped, and 8.7% were simultaneously socially isolated, socially inactive and lonely. The mortality rate was 29.9% in people, who were not lonely nor socially isolated nor inactive but 52.9% in the lonely, socially isolated and inactive. Both social inactivity and self-reported loneliness emerged as independent mortality risk indicators, whereas social isolation did not. The impact of social inactivity and self-reported loneliness was additive both in men and women and the survival curves diverged over time. Conclusions: Social inactivity and self-reported loneliness and their combination, particularly, are significant risk indicators in a general aged population whereas social isolation is not. (C) 2011 Elsevier Masson SAS and European Union Geriatric Medicine Society. All rights reserved.