Relation of late-life social activity with incident disability among community-dwelling older adults

Abstract

Background: We tested the hypothesis that a higher level of social activity was associated with decreased risk of incident disability in older adults.

Methods: Data came from older adults in the Rush Memory and Aging Project, an ongoing longitudinal cohort study of aging. Analyses were restricted to persons without clinical dementia and reporting no need for help performing any task in the particular functional domain assessed. Participants were followed for an average of 5.1 years (SD = 2.5). Social activity, based on 6 items (visiting friends or relatives; going to restaurants, sporting events, or playing games; group meetings; church/religious services; day or overnight trips; unpaid community/volunteer work), was assessed at baseline. Disability in basic activities of daily living, mobility disability, and instrumental activities of daily living was assessed annually. Proportional hazard models adjusted for age, sex, and education were used to examine the association between social activity and incident disability. Fully adjusted models included terms for depression, vascular diseases and risk factors, body mass index, social networks, and self-reported physical activity.

Results: In fully adjusted models, among 954 persons without baseline disability, the risk of developing disability in activities of daily living decreased by 43% (hazard ratio = 0.57, 95% confidence interval = 0.46, 0.71) for each additional unit of social activity. Social activity was also associated with decreased risk of developing mobility disability (hazard ratio = 0.69, 95% confidence interval = 0.54, 0.88) and disability in instrumental activities of daily living (hazard ratio = 0.71, 95% confidence interval = 0.55, 0.93).

Conclusions: Social activity is associated with a decreased risk of incident disability in activities of daily living, mobility, and instrumental activities of daily living, among community-dwelling older adults.

Figure 1.

Cumulative hazard of activity of daily living disability. From Cox proportional hazards models adjusted for age, sex, education, depression, vascular diseases and risk factors, body mass index, social networks, and self-reported physical activity. Solid line = 90th percentile of social activity (score = 3.3) and dotted line = 10th percentile of social activity (score = 1.8).

Figure 2.

Cumulative hazard of mobility disability. From Cox proportional hazards models adjusted for age, sex, education, depression, vascular diseases and risk factors, body mass index, social networks, and self-reported physical activity. Solid line = 90th percentile of social activity (score = 3.3) and dotted line = 10th percentile of social activity (score = 2.0).

Figure 3.

Cumulative hazard of instrumental activity of daily living disability. From Cox proportional hazards models adjusted for age, sex, education, depression, vascular diseases and risk factors, body mass index, social networks, and self-reported physical activity. Solid line = 90th percentile of social activity (score = 3.3) and dotted line = 10th percentile of social activity (score = 2.0).