Frailty as a novel predictor of mortality and hospitalization in individuals of all ages undergoing hemodialysis

Objectives: To quantify the prevalence of frailty in adults of all ages undergoing chronic hemodialysis, its relationship to comorbidity and disability, and its association with adverse outcomes of mortality and hospitalization.

Design: Prospective cohort study.

Setting: Single hemodialysis center in Baltimore, Maryland.

Participants: One hundred forty-six individuals undergoing hemodialysis enrolled between January 2009 and March 2010 and followed through August 2012.

Measurements: Frailty, comorbidity, and disability on enrollment in the study and subsequent mortality and hospitalizations.

Results: At enrollment, 50.0% of older (≥ 65) and 35.4% of younger (<65) individuals undergoing hemodialysis were frail; 35.9% and 29.3%, respectively, were intermediately frail. Three-year mortality was 16.2% for nonfrail, 34.4% for intermediately frail, and 40.2% for frail participants. Intermediate frailty and frailty were associated with a 2.7 times (95% confidence interval (CI) = 1.02-7.07, P = .046) and 2.6 times (95% CI = 1.04-6.49, P = .04) greater risk of death independent of age, sex, comorbidity, and disability. In the year after enrollment, median number of hospitalizations was 1 (interquartile range 0-3). The proportion with two or more hospitalizations was 28.2% for nonfrail, 25.5% for intermediately frail, and 42.6% for frail participants. Although intermediate frailty was not associated with number of hospitalizations (relative risk = 0.76, 95% CI = 0.49-1.16, P = .21), frailty was associated with 1.4 times (95% CI = 1.00-2.03, P = .049) more hospitalizations independent of age, sex, comorbidity, and disability. The association between frailty and mortality (interaction P = .64) and hospitalizations (P = .14) did not differ between older and younger participants.

Conclusions: Adults of all ages undergoing hemodialysis have a high prevalence of frailty, more than five times as high as community-dwelling older adults. In this population, regardless of age, frailty is a strong, independent predictor of mortality and number of hospitalizations.