Four different frailty models predict health outcomes in older patients with stable chronic obstructive pulmonary disease

Background Frail patients with chronic obstructive pulmonary disease (COPD) face a higher risk of adverse outcomes, but there is no clear consensus on which frailty measures are most suitable for COPD patients. Herein we evaluated the ability of frailty measurements in predicting 1-year acute exacerbation, hospitalization, and mortality in older patients with COPD. Methods A total of 302 patients [median age: 86 years (IQR: 80-90), 22.2% female] were admitted to the Department of Geriatric Medicine were prospectively enrolled in this study. Frailty status was assessed using the Fried Frailty Phenotype (FFP), Clinical Frailty Scale (CFS), Frailty Index of Accumulative Deficits (FI-CD), and Short Physical Performance Battery (SPPB). Cox proportional hazard regression and Poisson regression were used to evaluating the association of the adverse outcomes with frailty as assessed using the four instruments. The discrimination accuracy of these tools in predicting the 1-year all-cause mortality was also compared. Results Prevalence of frailty ranged from 51% (using FFP) to 64.2% (using CFS). The four frail instruments were associated with 1-year mortality. After an average follow-up time of 2.18 years (IQR: 1.56-2.62 years), frailty as defined by four instruments (except for FI-CD), was associated with death [FFP: Hazard ratio (HR) = 3.11, 95% confidence interval (CI) 1.30-7.44; CFS: HR = 3.68, 95% CI 1.03-13.16; SPPB: HR = 3.74, 95% CI 1.39-10.06). Frailty was also associated with acute exacerbation (using FFP) and hospitalization (using FFP, CFS, and FI-CD). Frail showed a moderate predictive ability [area under the curve ranging (AUC) 0.70-0.80] and a high negative predictive value (0.98-0.99) for 1-year mortality. Conclusions With the four different frailty assessment tools, frailty was associated with poor prognosis in older patients with stable COPD. The FFP, CFS, FI-CD, and SPPB instruments showed similar performance in predicting 1-year mortality.