Outcomes associated with comorbid anxiety and depression among patients with stable COPD: A patient registry study in China

Abstract

Background: Anxiety and depression are common among patients with chronic obstructive pulmonary disease (COPD), but the associations between psychiatric symptoms and specific COPD outcomes are uncertain.

Methods: Associations of psychiatric symptoms (anxiety and depression) and COPD outcomes (COPD Assessment Test (CAT), modified Medical Research Council dyspnea scale (mMRC), number of acute exacerbations and percentage predicted forced expiratory volume in 1 second (FEV₁% predicted)) sets were performed by canonical correlation analysis in 876 patients with COPD.

Results: In primary analysis, we discovered a statistically significant relationship between symptoms of anxiety/depression and COPD outcomes sets (1 - Λ = 0.11; P < .001). Symptoms of anxiety/depression and four COPD outcomes sets shared 11 % of variance. CAT was the main driver of the relationship (r_s = -0.930; r_s² = 0.8649) followed by mMRC (r_s = -0.632; r_s² = 0.3994) and exacerbation history (r_s = -0.478; r_s² = 0.2285); FEV₁% predicted did't make a significant contribution to the relationship (r_s = 0.134; r_s² = 0.018). In secondary analysis, women were associated with a stronger correlation based on the shared variance between psychiatric symptoms and COPD outcomes sets (17.4 %) than men (9.8 %).

Limitations: Some confounding factors such as education level, income, didn't be included. There were considerably fewer women enrolled in this study than men.

Conclusion: Psychiatric symptoms were associated with COPD subjective outcomes, and more related to COPD outcomes in women.

Keywords: Anxiety; COPD; Canonical correlation analysis; Depression; Multivariate.