Frailty phenotype, frailty index and risk of mortality in Chinese elderly population- Rugao longevity and ageing study

Background: To explore the associations of frailty phenotype and frailty index (FI) defined frailty and pre-frailty with mortality in a Chinese elderly population. Methods: Data of 1788 community-dwelling elders aged 70–84 years from the ageing arm of Rugao Longevity and Ageing Study, a prospective cohort study, were used. Frailty phenotype was defined using modified Fried’s phenotype (FP) criteria and FI was constructed using 45 health deficits. Mortality was ascertained using the Death Registry of Rugao's Civil Affairs Bureau. Results: During 3-year follow-up, 149 (8.3%) of the 1788 elderly subjects died. For frailty phenotype, about 9.5% of the elderly were frail and 43% were pre-frail. For FI, frail (FI > 0.21) was approximately 27.5%, and pre-frail (FI: 0.1–0.21) was approximately 51.3%. Highest mortality was observed among frail participants defined by both FP and FI criteria (all Log Rank P < 0.05). Frailty defined by the frailty index was associated with a 2.31 fold (95% CI 1.16–4.6) risk of all-cause death compared with robust elderly. Compared with the robust elderly, not only frailty (HR 2.24, 95% CI 1.31–3.83) defined by frailty phenotype but also pre-frailty (HR 1.51, 95% CI 1.03–2.21) was associated with risk of all-cause mortality. Conclusions: Frailty, defined by either phenotype or index, is associated with increased risks of mortality in elderly Chinese community population.