Frailty and survival of older Chinese adults in urban and rural areas: results from the Beijing Longitudinal Study of Aging.

Differences in frailty between rural and urban older adults have been demonstrated in developed countries. It is not understood how the apparently greater differences in living conditions between different types of regions in China may affect health and outcomes of older Chinese adults. Here, a frailty index (FI) based on the accumulation of health deficits was used to investigate health and survival differences in older Chinese men and women. We studied rural (n=1121) and urban (n=2136) older adults (55-97 years old) in the Beijing Longitudinal Study of Aging (BLSA), of whom 48.9% (rural) and 35.4% (urban) died over 8 years of follow-up. The FI was generated from 35 self-reported health deficits. The mean FI increased exponentially with age (r(2)=0.87) and was higher in women than in men. The death rate increased significantly with increases in the FI, but women showed a lower death rate than did men. The mean FI in urban older adults (0.12±0.10) was lower than that in their rural counterparts (0.14±0.12, p<0.001). Urban dwellers showed better survival compared with their counterparts in the rural areas. Adjusted by age, sex, and education level, the hazard ratio for death for each increment of the FI was 1.28 for urban people and 1.27 for rural people. Chinese urban dwellers showed better health and survival than rural dwelling older adults. The FI readily summarized health and mortality differences among different geographic regions, reflecting the impact of the environment, socioeconomics, and medical services on deficit accumulation and on survival.