Frailty, Hospitalization, and Mortality in Residential Aged Care.

Background: Frailty predicts mortality in residential aged care, but the relationship with hospitalization is inconsistent. The purpose of this study was to investigate and compare whether frailty is associated with hospitalization and mortality among residents of aged care services.
Methods: A prospective cohort study of 383 residents aged 65 years and older was conducted in six Australian residential aged care services. Frailty was assessed using the FRAIL-NH scale and a 66-item frailty index.
Results: Overall, 125 residents were hospitalized on 192 occasions and 85 died over the 12-month follow-up. Over this period, less than 3% of the nonfrail/vulnerable residents but more than 20% of the most frail residents died at the facility without hospitalization. Using the FRAIL-NH, residents with mild/moderate frailty had higher numbers of hospitalizations (adjusted incidence rate ratio 1.57, 95% confidence interval [CI] 1.11-2.20) and hospital days (incidence rate ratio 1.48, 95% CI 1.32-1.66) than nonfrail residents. Residents who were most frail had lower numbers of hospitalizations (incidence rate ratio 0.65, 95% CI 0.42-0.99) and hospital days (incidence rate ratio 0.39, 95% CI 0.33-0.46) than nonfrail residents. Similar patterns of associations with number of hospital days were observed for the frailty index. Most frail residents had a higher risk of death than nonfrail residents (for FRAIL-NH, adjusted hazard ratio 2.96, 95% CI 1.50-5.83; for frailty index, hazard ratio 5.28, 95% CI 2.05-13.59).
Conclusions: Residents with mild/moderate frailty had higher risk of hospitalization and death than nonfrail residents. Residents who were most frail had higher risk of death but lower risk of hospitalization than nonfrail residents.