Social Vulnerability, Frailty, and Their Association With Mortality in Older Adults Living in Rural Tanzania
Fiona Cooper, Emma Grace Lewis, Sarah Urasa, Louise Whitton, Harry Collin, Selina Coles, Greta K. Wood, Ali M. Ali, Deborah Mdegella, Joyce Mkodo, Francis Zerd, Catherine Dotchin, William K Gray, Richard Walker
Abstract
BACKGROUND: Social vulnerability correlates with frailty and is associated with mortality and disability. However, few studies have investigated this relationship outside of high-income country settings. This study aimed to produce and analyze a culturally adapted social vulnerability index (SVI) to investigate the relationship between social vulnerability, frailty, and mortality in older adults in Tanzania. METHODS: An SVI was produced using data from a cohort study investigating frailty in older adults in Tanzania. Variables were selected based on previous SVI studies using the categories established by Andrew et al. from the Canadian Study of Health and Aging, and National Population Health Survey. The SVI distribution was examined and compared with a frailty index (FI) produced from the same sample, using mutually exclusive variables. Cox regression survival analysis was used to investigate the association between social vulnerability, frailty, and mortality. RESULTS: A stratified cohort of 235 individuals were included in the study at baseline, with a mean age of 75.2 (SD 11.5). Twenty-six participants died within the follow-up period, with a mean of 503 days (range: 405-568) following the initial assessment. The SVI had a median score of 0.47 (interquartile range: 0.23, range: 0.14-0.86). Social vulnerability significantly predicted mortality when adjusting for age and gender, but not when also adjusting for frailty. CONCLUSIONS: Social vulnerability can be successfully operationalized and culturally adapted in Tanzania. Social vulnerability is associated with mortality in Tanzania, but not independently of frailty.