Social frailty as a predictor of mortality among older adults in four Colombian departments: evidence from the SABE survey

Social frailty, defined as a decline in social resources and participation, has emerged as a critical yet underrecognized dimension of vulnerability in older adults. While its association with adverse outcomes is increasingly documented, evidence from low- and middle-income countries remains limited. This study aimed to examine the association between social frailty and mortality among community-dwelling older adults in Colombia. We conducted a nested cohort study using data from the Colombian Health, Well-being, and Aging Survey (SABE; fieldwork 2015, official report 2016). The analysis was restricted to adults aged ≥ 60 years residing in four Colombian departments (Antioquia, Caldas, Risaralda, and Quindío). A total of 3,213 participants with verified vital status were included. Social frailty was measured using a multidimensional index incorporating functionality, social participation, emotional isolation, and perceived healthcare support. Individuals in the highest quartile (≥ 75th percentile) were classified as socially frail. Mortality follow-up was assessed through administrative linkage over 90 months. Cox proportional hazards models were used to estimate hazard ratios (HRs), adjusting for age and multimorbidity. Using the percentile-based threshold, 25.2% of participants were classified as socially frail, and 22.2% died during follow-up. In multivariable analysis, social frailty was independently associated with higher mortality risk (HR = 1.18; 95% CI: 1.01–1.39; p = 0.039). Age, sex and multimorbidity were also significantly associated with mortality. Social frailty was independently associated with all-cause mortality among older adults in this Colombian regional cohort. These findings suggest that incorporating social vulnerability measures into geriatric assessment may improve risk stratification and help identify individuals who could benefit from supportive interventions.