Analysis of frailty and survival from late middle age in the Beijing Longitudinal Study of Aging
1 Beijing Institute of Geriatrics, Beijing Hospital, Ministry of Health, Beijing, China
2 Department of Epidemiology and Social Medicine, Xuanwu Hospital, The Capital Medical University, Beijing, China
3 Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
4 National Research Council, Institute for Biodiagnostics-Atlantic, Halifax, Nova Scotia, Canada
5 Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia, Canada
6 Central for Health Care of the Elderly, QEⅡHealth Sciences Centre, Capital District Health Authority, Halifax, Nova Scotia, Canada
BMC Geriatrics 2011, 11:17 doi:10.1186/1471-2318-11-17Published: 20 April 2011
Frailty in individuals can be operationalized as the accumulation of health deficits, for which several trends have been observed in Western countries. Less is known about deficit accumulation in China, the country with the world's largest number of older adults.
This study analyzed data from the Beijing Longitudinal Study of Aging, to evaluate the relationship between age and deficit accumulation in men and women and to evaluate the impact of frailty on mortality. Community dwelling people aged 55+ years at baseline (n = 3275) were followed every two to three years between 1992 and 2000, during which time 36% died. A Frailty Index was constructed using 35 deficits, drawn from a range of health problems, including symptoms, disabilities, disease, and psychological difficulties.
Most deficits increased the eight-year risk of death and were more lethal in men than in women, although women had a higher mean level of frailty (Frailty Index = 0.11 ± 0.10 for men, 0.14 ± 0.12 for women). The Frailty Index increased exponentially with age, with a similar rate in men and women (0.038 vs. 0.039; r > 0.949, P < 0.01). A dose-response relationship was observed as frailty increased.
A Frailty Index employed in a Chinese sample, showed properties comparable with Western data, but deficit accumulation appeared to be more lethal than in the West.