The Impact of Frailty Status on Pulmonary Function and Mortality in Older Patients with Chronic Obstructive Pulmonary Disease

Objectives We aimed to evaluate the effect of frailty on lung function and disease outcomes in older adults with chronic obstructive pulmonary disease (COPD). Design Retrospective observational cohort. Setting and Participants At baseline, comprehensive geriatric assessment and pulmonary function tests were extracted from the case management care system of the geriatric department of a tertiary medical center. Measurements Frailty was assessed by the modified Rockwood frailty index. Kaplan-Meier survival and Cox proportional hazard analyses were used to analyze the primary outcome. Both the Friedman test and generalized estimating equations were used to evaluate the rate of decline in lung function. Results Among 151 enrolled older patients, comprising 69 non-COPD and 82 COPD subjects, the mean age was 80.9±8.3 years. After a median follow-up of 2.87 years, the serial forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC), and forced expiratory flow at 25–75% of FVC (FEF25–75%) showed significantly different slope changes between older COPD patients with and without frailty. The mortality hazard ratio (HR) was 2.53 for COPD without frailty and 3.62 for COPD with frailty, versus those without COPD. Among COPD patients, the factors most strongly associated with mortality were timed up-and-go, activities of daily living (ADLs), instrumental ADLs, FEV1/FVC, and serum HCO3-. After adjustment for potential confounders, ADLs and FEV1/FVC remained independent mortality predictors. Conclusion Among older patients with COPD, frailty was common and associated with pulmonary function decline, and mortality risk was higher in frail than in non-frail subjects.