Co-morbid association of depression and COPD: a population-based study.

OBJECTIVES: Depression occurs commonly among patients with COPD, but the independent association of depression and COPD and the effect of depression on COPD outcomes are not well established.
METHOD: A population sample of 2402 Chinese aged >or=55 with and without COPD (characteristic symptoms of chronic cough, sputum or breathlessness and airflow obstruction and FEV(1)/FVC<0.70) was assessed on Geriatric Depression Scale (score>or=5), dependence on basic activities of daily living (ADL), SF-12 health status, smoking and medication behaviour.
RESULTS: The 189 respondents with COPD showed higher depressive symptoms prevalence (22.8%) than 2213 respondents without COPD (12.4%); multivariate odd ratio (OR) was 1.86; 95% CI, 1.25-2.75 after controlling for confounding risk factors. In multivariate analyses of respondents with COPD, those who were depressed (N=43), compared to those who were not (N=146), were more likely to report ADL disability (OR=2.89, p=0.049) poor or fair self-reported health (OR=3.35, p=0.004), poor SF-12 PCS scores (OR=2.35, p=0.041) and SF-12 MCS scores (OR=4.17, p<0.001).
CONCLUSION: Depressive symptoms were associated with COPD independent of known risk factors. In COPD participants, depressive symptoms were associated with worse health and functional status and self-management.