Ryu YJ, et al. Depression and anxiety in chronic airway lung diseases 53 Table 1. Baseline characteristics of the study population Parameters Age, yr Male gender Body mass index, kg/m2 Smoking habits Ex-smoker / Current smoker Median pack-years Post-bronchodilator FVC, % predicted Post-bronchodilator FEV1, % predicted Post-bronchodilator FEV1/FVC ratio Hemoglobin, g/dL Albumin, g/dL PaO2, mmHg (room air) PaCO2, mmHg (room air) Healthy control (n = 73) 66 (51 - 89) 33 (45) 23.8 ± 3.2 14 / 1 20 (1 - 40) 98.8 ± 14.2 102.7 ± 16.7 84.9 ± 10.6 13.1 ± 1.6 4.1 ± 0.4 88.2 ± 3.6 38.9 ± 3.5 COPD (n = 84) 67 (45 - 88) 80 (95)a 22.6 ± 3.0 59 / 25 40 (15 - 100)a 81.9 ± 17.8a 59.5 ± 24.8a 51.9 ± 13.3a 14.3 ± 1.7a 4.1 ± 0.5 79.1 ± 16.5 40.8 ± 6.8 Chronic airway lung diseases Bronchial asthma (n = 37) 56 (45 - 80)a,b 16 (43)b 24.9 ± 3.6b 7 / 3 20 (5 - 30)b 82.8 ± 18.7a 71.7 ± 21.1a,b 63.2 ± 10.2a,b 13.7 ± 1.8 4.3 ± 0.5 84.7 ± 13.2 39.5 ± 4.7 Bronchiectasis (n = 33) 62 (45 - 83)a,b 15 (46)b 21.3 ± 3.3a 9 / 1 18 (2 - 70)b 62.6 ± 18.2a,b 55.0 ± 19.0a 64.3 ± 16.6a,b 13.2 ± 1.4b 3.9 ± 0.5 77.9 ± 20.3 42.8 ± 10.2a Values are expressed as the mean ± SD, median (range), or number (%). COPD, chronic obstructive pulmonary disease; FVC, forced vital capacity; FEV1, forced expiratory volume one second. a p < 0.05 compared to healthy controls. b p < 0.05 compared to patients with COPD. Statistical analysis SPSS version 13.0 (SPSS Inc., Chicago, IL, USA) was used for the statistical analysis. A p value of < 0.05 was considered significant. Group comparisons for categorical variables were performed using Pearson’s chi-square test or Fisher’s exact test. To compare groups of patients, we used ANOVAs for normally distributed data and the Kruskal-Wallis test for non-normally distributed data. For comparisons between two groups, Student’s t-test and the Mann-Whitney U test were used for normally and non- normally distributed data, respectively. Pearson’s correlation was used to assess the association between anxiety and depression. To evaluate the risk factors for depression, multivariate logistic regression analysis was performed incorporating all factors that obtained values of p < 0.05 in the bivariate analyses. RESULTS General characteristics of patients with chronic airway lung diseases The demographic characteristics of the 73 healthy controls and the 154 patients with chronic airway lung diseases who completed the study are summarized in Table 1. The median age of all 227 subjects, 65 years (range, 45 to 89), was similar in the control and COPD groups. However, patients with bronchial asthma and bronchiectasis were slightly younger than were healthy controls or patients with COPD. Prevalence of depression and anxiety in patients with chronic airway lung diseases Table 2 shows the median scores on the BDI and both STAI subscales for patients with COPD, bronchial asthma, and bronchiectasis. Patients with COPD obtained the highest depression scores, followed by patients with bronchiectasis, and then by those with bronchial asthma, in decreasing order. The BDI scores and frequency of depression for the healthy controls and the patients with bronchial asthma did not differ significantly. Depression was identified in 55% of the patients with COPD (OR, 2.7; p = 0.004), 55% of those with bronchiectasis (OR, 3.0; p = 0.016), 41% of those with bronchial asthma (OR, 1.5; p = 0.293), and 30% of the healthy controls. In a subgroup analysis of patients with COPD, increased frequency of depression was correlated with increased disease severity according to the GOLD stages (p = 0.004); the frequency of depression among those with mild disease levels was 23% (5/22); with moderate, 54% (14/26); with severe, 72% (21/29); and with very severe, 71% (5/7). In terms of the severity categories, 40% (19/48) of the patients with