title: Prevalence of depressive symptoms in patients with chronic obstructive pulmonary disease: a systematic review, meta-analysis and meta-regression.
abstract: OBJECTIVE
  This meta-analysis was aimed to evaluate the differences in aggregated prevalence of depressive symptoms among people with chronic obstructive pulmonary disease (COPD) as compared to controls without COPD and to determine underlying moderators to explain potential heterogeneity of prevalence.
  
  
  METHODS
  A meta-analysis of published work was performed using the random effect model. A total of eight studies were identified. We calculated the differences in prevalence proportion of depressive symptoms in patients with COPD versus controls. Meta-regression and subgroup analysis were performed to identify factors that may contribute to heterogeneity.
  
  
  RESULTS
  The prevalence proportion of depressive symptoms was found to be significantly higher (pooled odds ratio: 2.81; 95% CI: 1.69-4.66) among 39587 individuals with COPD as compared to 39,431 controls (24.6%, 95% CI: 20.0-28.6% vs. 11.7%, 95% CI: 9-15.1%). Meta-regression was conducted to account for the heterogeneity of the prevalence proportion, but moderators like mean age, gender, mean FEV(1) and proportion of current smokers among COPD patients were nonsignificant and could not explain heterogeneity in prevalence of depressive symptoms. Subgroup analyses showed no significant differences based on different methods of assessment of depressive symptoms and countries sampled.
  
  
  CONCLUSIONS
  This meta-analytical review identified higher prevalence of depressive symptoms among COPD patients, and meta-regression showed that demographic and clinical factors were not the determinants of heterogeneity in prevalence of depressive symptoms.
authors: Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Melvyn W B
authors: MW
authors: Zhang
authors: Roger C M
authors: RC
authors: Ho
authors: Mike W L
authors: MW
authors: Cheung
authors: Erin
authors: E
authors: Fu
authors: Anselm
authors: A
authors: Mak