Background: Anxiety and depression are prevalent comorbidities in COPD and are related to a worse course of disease. The present study examined the impact of anxiety and depression on functional performance, dyspnea, and quality of life (QoL) in patients with COPD at the start and end of an outpatient pulmonary rehabilitation (PR) program.
Methods: Before and after PR, 238 patients with COPD (mean FEV(1) % predicted = 54, mean age = 62 years) underwent a 6-min walking test (6MWT). In addition, anxiety, depression, QoL, and dyspnea at rest, after the 6MWT, and during activities were measured.
Results: Except for dyspnea at rest, improvements were observed in all outcome measures after PR. Multiple regression analyses showed that before and after PR, anxiety and depression were significantly associated with greater dyspnea after the 6MWT and during activities and with reduced QoL, even after controlling for the effects of age, sex, lung function, and smoking status. Moreover, before and after PR, anxiety was related to greater dyspnea at rest, whereas depression was significantly associated with reduced functional performance in the 6MWT.
Conclusions: This study demonstrates that anxiety and depression are significantly associated with increased dyspnea and reduced functional performance and QoL in patients with COPD. These negative associations remain stable over the course of PR, even when improvements in these outcomes are achieved during PR. The results underline the clinical importance of detecting and treating anxiety and depression in patients with COPD.