To assess the relationship between social network size and prospective mortality risk among a large sample of older, Caucasian women.
The study included 7524 Caucasian community-dwelling women, age 65 or older (mean age = 74.1), who participated from four U.S. communities. Study participants completed a protocol that included anthropomorphic and health assessments at baseline and the Lubben Social Network Scale at year 2. We followed participants for an average of 6 years after they had completed the year-2 assessment. We used hospital records and a copy of the participant's official death certificate to document mortality and cause of death in accordance to ICD-9 revision codes.
A total of 1451 deaths (19.3% of sample) were observed over follow-up, 215 (3.4%) due to cardiovascular causes. Higher social network scores were a robust predictor of lower multivariate-adjusted mortality (RR = 0.92, 95% CI = 0.86-0.98), controlling for age, comorbid disease, body mass, smoking, depression, and education. However, social network benefits were attenuated after controlling for marital status. Married participants showed lower total (RR = 0.83, 95% CI = 0.74-0.94) and CVD (RR = 0.59, 95% CI = 0.43-0.81) covariate-adjusted death rates compared with unmarried participants.
Social network scores and marriage were each associated with reduced prospective mortality risk among older women. The relationships shown here suggest that much of the protection afforded by larger social networks in older women results from marriage rather than other forms of social relationships. Mechanisms at the physiological or behavioral level explaining social relationship benefits remain important areas for future research.