Disability as a function of social networks and support in elderly African Americans and Whites: the Duke EPESE 1986--1992

OBJECTIVES: We examined the association of structural and functional aspects of social relationships with change in disability, and the degree to which race modifies these associations. METHODS: Data are from a population-based sample of 4,136 African Americans and Whites aged > or = 65 living in North CAROLINA: Disability data were collected during seven consecutive yearly interviews and summarized in two outcome measures. Measures of social relationships included five measures representing network size, extent of social interaction, and specific type of relationships, as well as instrumental and emotional support. Weighted proportional odds models were fitted to model disability as a function of baseline social network and support variables, and the interaction of each variable with follow-up time. RESULTS: Network size and social interaction showed significant negative associations with disability risks, which did not vary by race, or as a function of time. Social interaction with friends was associated with a reduced risk for disability, but social interaction with children or relatives was not related to disability. Instrumental support was associated with a significantly increased disability risk, with a greater adverse effect among Whites than African AMERICANS: Emotional support was not associated with disability, but a protective effect for ADL disability was found after controlling for its intercorrelation with instrumental support. DISCUSSION: The findings provide further evidence for the role of social relationships in the disablement process, although not all types of social relationships may be equally beneficial. Furthermore, these associations may be more complex than simple causal effects. There were few racial differences in the association of social relationships with disability, with the possible exception of instrumental support, which may allude to possible sociocultural differences in the experience of instrumental support exchanges.