Abstract
OBJECTIVES: To compare levels of social isolation in aging veterans with and without the human immunodeficiency virus (HIV) and determine associations with hospital admission and mortality. DESIGN: Longitudinal data analysis. SETTING: The Veterans Aging Cohort Study (VACS), at eight VA Medical Centers nationally. PARTICIPANTS: Veterans aged 55 and older enrolled in VACS from 2002 to 2008 (N = 1,836). MEASUREMENTS: A Social Isolation Score (SIS) was created using baseline survey responses about relationship status; number of friends and family and frequency of visits; and involvement in volunteer work, religious or self-help groups, and other community activities. Scores were compared according to age and HIV status, and multivariable regression was used to assess effects of SIS on hospital admission and all-cause mortality. RESULTS: Mean SIS was higher for HIV-positive (HIV+) individuals, with increasing difference according to age (P = .01 for trend). Social isolation was also more prevalent for HIV+ (59%) than uninfected participants (51%, P < .001). In multivariable regression analysis of HIV+ and uninfected groups combined, adjusted for demographic and clinical features, isolation was independently associated with greater risk of incident hospitalization (hazard rate (HR) = 1.25, 95% confidence interval (CI) = 1.09-1.42) and risk of all-cause mortality (HR=1.28, 95% CI = 1.06-1.54). Risk estimates calculated for HIV+ and uninfected groups separately were not significantly different. CONCLUSION: Social isolation is associated with greater risk of hospitalization and death in HIV+ and uninfected older veterans. Despite similar effects in both groups, the population-level effect of social isolation may be greater in those who are HIV+ because of the higher prevalence of social isolation, particularly in the oldest individuals.