Time-varying social support and time to death in the cardiovascular health study

Objectives: There is a consensus that social connectedness is integral for a long, healthy life. However, studies of social support and survival have primarily relied on baseline social support measures, potentially missing the effects of fluctuations of perceived support over time. This is especially important for older adults who experience increased changes in disability. This study examined whether among older adults time-varying perceived social support was associated with time to death (main effect model of support) and whether time-varying disability was a modifier (stress-buffering model of support). Gender and marital status were also examined as modifiers. Methods: Older adults in the Cardiovascular Health Study (N = 5,201) completed self- report measures of demographics and psychological health and clinical risk factors for mortality at baseline (1989 -1990). Perceived social support and disability were measured from baseline through Wave 11 (1998 -1999). Cox regression of time to death with timevarying covariates was performed. Results: Time-varying as well as baseline-only perceived social support was associated with greater survival in the unadjusted models but not after adjustment. Gender, marital status, and time-varying disability were not significant modifiers. Conclusions: In contrast with the previously reported association between baseline individual differences in perceived social support and time to death, older adults' baseline-only and fluctuating perceptions of perceived support over time were not associated with time to death after adjustment for other clinical physical and psychological risk factors. Research is needed to identify other relationship factors that may be more informative as time-varying predictors of health and longevity in large longitudinal data sets.