Bridging Disciplinary Boundaries (January 11 - 14, 2007)

PURPOSE: It is well-established that social ties influence the physical and psychological well-being of older people. Empirical evidence suggests with considerable consistency that individuals with strong relationships with family and friends experience better physical and mental health. However, less attention has been paid to the effect of health on social ties, and the reciprocal relationship between the two. The purpose of this research is to examine the relationship between health and social ties with family and friends. Using a theoretical framework that encompasses social causation and social selection, this research aimed to answer the following questions: (1) Do social ties influence, or are they influenced by, health in older adults? (2) Can social ties be both predictor and outcome of health in older adults? METHODS: Longitudinal data from the UCLA Medicare Screening and Health Promotion Trial, a panel design study of community-dwelling older adults, were used to examine predictive and reciprocal relationships between social ties and physical and mental health over a 5-year period. Social ties were measured by the Lubben Social Network Scale. Physical health was measured by the Subjective Self-Health Rating and two functional scales, Basic Activities of Daily Living (BADL) and Instrumental Activities of Daily Living (IADL). Mental health was measured by the Mental Health Inventory and the Center for Epidemiological Studies scale for Depressive Symptoms. Multivariate analyses, (confirmatory factor analysis and linear growth modeling) were used to develop cross-sectional and longitudinal measurement models that tested hypothesized relationships between social ties and health. RESULTS: Social ties were found to influence health, such that social ties positively predicted the growth (change) rate of physical functioning as measured by IADLs. Weak social ties, for example, predicted a decreased capacity over time to perform certain IADL tasks. This supports social causation, specifically, the direct (main) effects model, which posits that social ties have direct benefits for the health of older people independent of the presence or absence of stress. In addition, social ties were found to be influenced by selected indicators of physical and mental health: IADLs and depressive symptoms affected the growth rate of social ties over time, such that lower levels of IADL functioning and higher levels of psychological distress predicted weaker social ties over time. This supports social selection, which posits that healthy people are more likely to have strong social ties because they are healthy. Conversely, poor physical or mental health hinders a person's capacity to participate and maintain social relationships. These results confirm that social ties influence, and are influenced by, physical functioning, thus suggesting a reciprocal relationship between social ties and health. IMPLICATIONS: In view of the empirical evidence from this and other studies that have firmly established the benefits of social ties for the health of older people, social work practitioners and educators, policy-makers, gerontological researchers, and advocates of elders and their families should continue to examine and promote a supportive environment for older individuals and their social ties.