Social Vulnerability, Frailty, and Their Association With Mortality in Older Adults Living in Rural Tanzania.

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.

The prevalence and characteristics of frailty by frailty phenotype in rural Tanzania.

BACKGROUND: The frailty phenotype is defined by the presence of three from the following five clinical features: weakness, slow walking speed, unintentional weight loss, exhaustion, and low physical activity. It has been widely applied in different research and clinical contexts, including across many low and middle-income countries. However, there is evidence that the operationalisation of each component of the frailty phenotype significantly alters its characteristics and predictive validity, and care is needed when applying the phenotype across settings. The study's objective was to operationalise the frailty phenotype in a rural Tanzanian population of older community-dwelling adults. METHODS: Consenting adults aged ≥60 years, and resident in five randomly selected villages of Hai district Demographic Surveillance Site, were eligible to participate in this cross-sectional study. From a screened sample of 1207 older adults, 235 were randomised and consented to an assessment of their frailty status by the frailty phenotype. Trained research fieldworkers (Tanzanian medical doctors and nurses) carried out measurements and questionnaires at local village centres or at participants' homes. RESULTS: The prevalence of the frailty phenotype, calculated from complete data for 196 participants, was 9.25% (95% CI 4.39-14.12) When missing data were counted as meeting frailty criterion (i.e. missing due to inability to perform an assessment), the prevalence increased to 11.22% (95% CI 7.11-15.32). Frailty by phenotype criteria was more common in older age groups, and was associated with self-assessed poor health and depression symptoms. CONCLUSIONS: Frailty can be successfully estimated using the frailty phenotype, however there are challenges in its operationalisation cross-culturally. Further work is needed to explore the potential clinical application of the frailty phenotype in such settings.