Abstract
BACKGROUND: Frailty is a clinically recognizable state of reduced resilience to stressors and increased vulnerability to adverse outcomes. The majority of studies have focused on the prevalence and risk factors of frailty, while the incidence of frailty has not been well documented, especially in less developed regions including China-a country that has the largest aging population in the world. We investigated the incidence of frailty among non-frail Chinese older adults by sociodemographic characteristics, disease burden, and geographic region. METHODS: Participants were 4939 adults aged ≥60 years from the China Health and Retirement Longitudinal Study, a cohort study of a nationally representative sample of middle-aged and older community-dwelling adults from 28 provinces in China. Frailty was assessed by an adapted version of the well-validated Fried's physical frailty phenotype, in which five criteria were included: weakness, slowness, exhaustion, physical inactivity, and shrinking. RESULTS: Over an average of 2.1 years of follow-up (10,514.2 person-years), the weighted incidence rate of frailty was 60.6 per 1000 person-years; the incidence rate was 28.8 and 86.6 per 1000 person-years for those who were initially robust and prefrail, respectively. Participants who were older and widowed, had lower education and household income, lived in rural areas, and had higher burden of chronic conditions had higher frailty incidence. Frailty incidence ranged from 44.8 per 1000 person-years in the Southeast to 93.0 per 1000 person-years in the Northwest. CONCLUSIONS: Incidence rate of frailty was 60.6 per 1000 person-years among community-living Chinese adults aged ≥ 60 years. Substantial sociodemographic and geographical disparities exist in frailty incidence.