Social frailty increases the risk of all-cause mortality: A longitudinal analysis of the English Longitudinal Study of Ageing

Objectives: Social frailty is a common condition in older people, but its consequences are largely unknown. Therefore, in this longitudinal analysis, we aimed to investigate the association between social frailty and risk of all-cause mortality in a large sample of older people. Design: Longitudinal, cohort. Settings and participants: Older people participating to the English Longitudinal Study of Ageing (ELSA). Methods: Social frailty was defined based on financial difficulty, household status, social activity, and contacts with other people: social frailty was defined as ≥2 points, social pre-frailty (1 point), and robustness (0 points). Survival status during ten years of follow-up was assessed using administrative data. Cox proportional hazard models were used to estimate adjusted hazard ratios (HR) and 95 % confidence intervals (95 % CI) of the association between social frailty status and all-cause mortality. Results: At baseline, compared to social robust participants, social frail subjects reported a significant higher presence of potential risk factors for all-cause mortality. During the ten years of follow-up, after adjusting for 10 potential confounders, social frailty at baseline (vs. robustness) was associated with a significantly higher risk of death (HR = 1.31; 95 % CI: 1.04–1.64; p = 0.02), whilst social pre-frail was not. Among the single factors contributing to social frailty, poverty increased the risk of all-cause mortality by approximately 60 % (HR = 1.60; 95 % CI: 1.33–1.93; p < 0.0001) as well as living alone (HR = 1.46; 95 % CI: 1.10–1.94; p = 0.009). Conclusions and implications: Social frailty was significantly associated with all-cause mortality in a large cohort of older people, highlighting the importance of identifying this phenomenon in older adults to inform targeted intervention efforts.