Frailty as a predictor of all-cause mortality in older men and women

Abstract

Aims: To investigate the modifying effect of sex on the association between frailty and all-cause mortality, and to determine the effects of changes in frailty status on mortality.

Methods: This population-based study comprised 654 persons aged 76-100 years (mean age 82 ± 4.6 years). Frailty status was assessed at baseline in 2005, and reassessed in 2007 (n=546) using the Cardiovascular Health Study criteria. Death dates were received from the official register until the end of 2009. The associations between frailty, changes in frailty and mortality were investigated using Cox regression models.

Results: At baseline, 93 (14%) participants were classified as frail, and 311 (48%) as pre-frail. Over the 4-year follow up, 173 (27%) baseline respondents died. The mortality risk for participants who were frail at baseline was 2.7 (95% CI 1.6-4.5) compared with the robust. In the fully adjusted model, the association was significant for women (HR 2.8, 95% CI 1.5-5.3), and of borderline significance for men (HR 2.4, 95% CI 1.0-5.9). In men, pre-frailty and frailty were both associated with increased mortality risk only in the age-adjusted model (pre-frailty HR 2.3, 95% CI 1.2-4.5; frailty HR 4.0, 95% CI 1.9-8.9). Decline in frailty status during the 2-year follow-up period also markedly increased the risk for mortality over the succeeding 2 years.

Conclusions: Frailty is strongly associated with higher mortality, especially among women. Among men, the association was explained by baseline functional capacity, comorbidity and lifestyle factors. Changes in frailty status should also be taken into consideration when planning geriatric care, as such changes could indicate a more rapid decline in health.

Keywords: epidemiology; frailty; geriatric medicine; public health; survival analysis.