The association between depressive symptoms and acute exacerbations of COPD

Background: Depression is an important comorbidity for patients with chronic obstructive pulmonary disease (COPD). The association between depression and acute exacerbations of COPD is unknown. This study was designed to determine the frequency of COPD exacerbations in outpatients with and without depressive symptoms. Methods: In this retrospective cohort study, patients with a primary diagnosis of COPD were followed for 1 year after discharge from a pulmonary rehabilitation program and the frequency of exacerbations was recorded. Upon completion of the program, all patients were administered the Short-Form 36 Health Survey (SF-36), which contains a mental health domain. Patients were classified as having depressive symptoms based on their domain score, which was separately validated in a second population of patients. Results: Of the 194 patients with COPD who completed the pulmonary rehabilitation program, 32 (16.5%) had depressive symptoms. There were no differences in terms of age, race, pack-years, forced expiratory volume in 1 second (FEV₁), 6-minute walk distance, body mass index, use of supplemental oxygen, use of inhaled steroids, or the Charlson Comorbidity Index between patients with and without depressive symptoms. Patients with depressive symptoms had more exacerbations in the following year (1.91 vs. 1.36; p = 0.02), were 2.8 times more likely to have ever had an exacerbation (95% confidence interval (CI), 1.1-7.3; p = 0.03), and suffered a first exacerbation earlier (148 days compared with 266 days; p = 0.04) than nondepressed patients. Conclusions: COPD patients with depressive symptoms have a significantly higher risk for exacerbations. Early screening for depression in patients with COPD may help identify those patients at higher risk for subsequent exacerbations.