The influence of social relations on mortality in later life: a study on elderly Danish twins.

PURPOSE: We examined whether the presence of a spouse and the frequency of interaction with children, relatives, and friends significantly influence the risk of dying in late life. We assessed these effects separately by gender, controlling for self-reported health. In addition, we examined whether interaction with the co-twin has a different impact on mortality for identical and fraternal twins. DESIGN AND METHODS: The data set consists of 2,147 Danish twins aged 75 years and older, who were followed prospectively from 1995 to 2001. We modeled the effect of social ties on mortality by using event history analysis. RESULTS: Survival is extended by having a spouse and close ties with friends and the co-twin. However, contact frequency with friends and the co-twin is significant, respectively, only for women and identical twins. IMPLICATIONS: Investigating social relations sheds light on the life span of individuals older than 75 years of age. We stress the importance of social relations beyond the presence of the spouse for survival even at very old ages.