Frailty as a Predictor of Mortality in Late-Life Depression: A Prospective Clinical Cohort Study

OBJECTIVE: Frailty is a clinical phenotype that predicts negative health outcomes, including mortality, and is increasingly used for risk stratification in geriatric medicine. Similar to frailty, late-life depression is also associated with increased mortality rates. Therefore, we examined whether frailty and frailty-related biomarkers predict mortality among depressed older patients.

METHODS: In our study of 378 older patients aged ≥ 60 years with a depressive disorder (DSM-IV criteria), we examined whether frailty predicts time-to-death during a 6-year follow-up using Cox proportional hazard regression analyses adjusted for confounders. Baseline data were collected from 2007 to September 2010. Frailty was defined according to the Fried Frailty Phenotype criteria (muscle weakness, slowness, exhaustion, low activity level, unintended weight loss). Similarly, we examined the predictive value of 3 inflammatory markers, vitamin D level, and leukocyte telomere length and whether these effects were independent of the frailty phenotype.

RESULTS: During follow-up, 27 (26.2%) of 103 frail depressed patients died compared with 35 (12.7%) of 275 non-frail depressed patients (P < .001). Adjusted for confounders, the number of frailty components was associated with an increased mortality rate (hazard ratio = 1.38 [95% CI, 1.06-1.78], P = .015). All biomarkers except for interleukin 6 were prospectively associated with mortality, but only higher levels of high-sensitivity C-reactive protein and lower levels of vitamin D were independent of frailty associated with mortality.

CONCLUSIONS: In late-life depression, frailty identifies older patients at increased risk of adverse negative health outcomes. Therefore, among frail depressed patients, treatment models that include frailty-specific interventions might reduce mortality rates.