Frailty Phenotype and Cause-Specific Mortality in the United States.

Background: Frailty is a common condition among older adults increasing risk of adverse outcomes including mortality; however, little is known about the incidence or risk of specific causes of death among frail individuals.

Methods: Data came from the Health and Retirement Study (HRS; 2004-2012), linked to underlying cause-of-death information from the National Death Index (NDI). Community-dwelling HRS participants aged 65 and older who completed a general health interview and physical measurements (n = 10,490) were included in analysis. Frailty was measured using phenotypic model criteria-exhaustion, low weight, low energy expenditure, slow gait, and weakness. Underlying causes of death were determined using International Classification of Diseases, Version 10 codes. We used Cox proportional hazards and competing risks regression models to calculate and compare incidence of cause-specific mortality by frailty status.

Results: During follow-up, prefrail and frail older adults had significantly greater hazard of all-cause mortality compared to individuals without symptoms (adjusted hazard ratio [HR] prefrail: 1.85, 95% CI: 1.51, 2.25; HR frail: 2.75, 95% CI: 2.14, 3.53). Frailty was associated with 2.96 (95% CI: 2.17, 4.03), 2.82 (95% CI: 2.02, 3.94), 3.48 (95% CI: 2.17, 5.59), and 2.87 (95% CI: 1.47, 5.59) times greater hazard of death from heart disease, cancer, respiratory illness, and dementia, respectively.

Conclusions: Significantly greater risk of mortality from several different causes should be considered alongside the potential costs of screening and intervention for frailty in subspecialty and general geriatric clinical practice. Findings may help investigators estimate the potential impact of frailty reduction approaches on mortality.