OBJECTIVES:To evaluate the prevalence and 10-year outcomes of frailty in older adults in relation to deficit accumulation. DESIGN: Prospective cohort study. SETTING: The National Population Health Survey of Canada, with frailty estimated at baseline (1994/95) and mortality follow-up to 2004/05. PARTICIPANTS: Community-dwelling older adults (N 5 2,740, 60.8% women) aged 65 to 102 from 10 Canadian provinces. During the 10-year follow-up, 1,208 died. MEASUREMENTS: Self-reported health information was used to construct a frailty index (Frailty Index) as a proportion of deficits accumulated in individuals. The main outcome measure was mortality. RESULTS: The prevalence of frailty increased with age in men and women (correlation coefficient 5 0.955-0.994, Po.001). The Frailty Index estimated that 622 (22.7%, 95% confidence interval (CI) 5 21.0-24.4%) of the sample was frail. Frailty was more common in women (25.3%, 95% CI 5 23.2-27.5%) than in men (18.6%, 95% CI 5 15.9-21.3%). For those aged 85 and older, the Frailty Index identified 39.1% (95% CI 5 31.3-46.9%) of men as frail, compared with 45.1% (95% CI 5 39.7-50.5%) of women. Frailty significantly increased the risk of death, with an age-and sex-adjusted hazard ratio for the Frailty Index of 1.57 (95% CI 5 1.41-1.74). CONCLUSION: The prevalence of frailty increases with age and at any age lessens survival. The Frailty Index approach readily identifies frail people at risk of death, presumably because of its use of multiple health deficits in multidimensional domains. J Am Geriatr Soc 58:681-687, 2010.

Relative fitness and frailty can be defined in relation to deficit accumulation. In population studies from developed countries, deficit accumulation is robustly associated with mortality and with age. In samples (e.g., clinical/institutional) in which most people are frail, there is no relationship with age, suggesting that there are maximal values of deficit accumulation beyond which survival is unlikely.