Social participation and survival at older ages: is the effect driven by activity content or context?

This study tested the hypothesis that time spent on social activities (i.e., in direct interaction with others) and time spent in social contexts (i.e., while others are present) is associated with survival in persons aged 70 and older. An observational study with mortality follow-ups was carried out in the former West Berlin, Germany (Berlin Aging Study). The sample was stratified by age and sex, and consisted of 473 persons aged 70 to 103 years. Social activity and social context measures were assessed in 1990-1993 by structured interviews in the participants' homes. Cox regression was used to model survival from time of interview. The main outcome measure was survival on 1 August 2003. Time spent on social activities was revealed as a predictor of survival only in analyses that did not control for confounding factors. In contrast, time spent in context "with friends" was significantly related to increased survival (relative risk=0.76, 95% confidence interval 0.59 to 0.99) even after several confounding factors were controlled for. This study suggests that time spent with friends affords a survival advantage among older adults, above and beyond the effects of other leisure activities. Future research on social participation and survival may benefit from an examination of the interaction between activity content and social context.