Table 1 General characteristics of participants in CODA and KOLD cohort studies

From: A comparative study of chest CT findings regarding the effects of regional dust exposure on patients with COPD living in urban areas and rural areas near cement plants

  CODA (n = 186) KOLD (n = 547)   
  N Mean ± SD or N (%) N Mean ± SD or N (%) P log-formed P
P for
log-transformed value
Age (year) 186 72.5 ± 7.1 547 67.4 ± 8.0 < .0001  
 40 ~ 59   8 (4.3)   90 (16.5) < .0001  
 60 ~ 69   50 (26.9)   232 (42.4)   
 70 ~ 79   100 (53.8)   195 (35.6)   
 80 ~ 96   28 (15.1)   30 (5.5)   
Gender (N, %)       
 Male   184 (98.9)   530 (96.9) 0.1318  
 Female   2 (1.1)   17 (3.1)   
Education       
 < Elementary school   41 (22.0)   45 (9.2) < .0001  
 Elementary school   84 (45.2)   91 (18.6)   
 Middle school   28 (15.1)   109 (22.3)   
 ≥ High school   33 (17.7)   243 (49.8)   
Height (cm)   163.0 ± 6.3   165.6 ± 6.4 < .0001  
Weight (kg)   60.2 ± 10.1   63.2 ± 9.9 0.0004  
BMI (kg/m2)   22.6 ± 3.2   23.0 ± 3.1 0.1491  
 < 23.0   100 (53.8)   263 (48.2) 0.3776  
 23.0 ~ 24.9   44 (23.7)   153 (28.0)   
 ≥ 25.0   42 (22.6)   130 (23.8)   
Smoking (yes)       
 Current   67 (36.0)   193 (35.3) 0.8558  
 Former   119 (64.0)   354 (64.7)   
Pack-year of smoking   34.4 ± 24.7   46.4 ± 25.8 < .0001  
History of chronic bronchitis (N, %)       
 No   154 (93.3)   427 (89.1) 0.1182  
 Yes   11 (6.7)   52 (10.9)   
Charlson comorbidity index (N, %)       
 0   107 (57.5)   362 (75.6) < .0001  
 1   45 (24.2)   84 (17.5)   
 ≥ 2   34 (18.3)   33 (6.9)   
Hospitalized exacerbations in the prior year (N, %)     
 0   175 (94.1)   403 (81.1) 0.0001  
 1   4 (2.2)   45 (9.1)   
 ≥ 2   7 (3.8)   49 (9.9)   
Hospitalized exacerbations in the prior year (N, %)     
 No   175 (94.1)   403 (80.0) < .0001  
 Yes   11 (5.9)   101 (20.0)   
COPD medications*(N, %)     
 No   129 (69.4)   163 (36.6) < .0001  
 Yes   57 (30.6)   282 (63.4)   
History of biomass exposure (N, %)       
 No   67 (36.0)   123 (25.4) 0.0061  
 Yes   119 (64.0)   362 (74.6)   
CAT score 186 17.10 ± 9.50 219 12.20 ± 7.80 < .0001  
Pulmonary function test       
 Pre-bronchodilator FEV1 (L) 186 1.79 ± 0.54 546 1.58 ± 0.58 < .0001  
 Pre-bronchodilator FVC (L) 186 3.01 ± 0.75 546 3.37 ± 0.81 < .0001  
 Post-bronchodilator FEV1 (L) 186 1.89 ± 0.52 547 1.72 ± 0.59 0.0004  
 Post-bronchodilator FVC (L) 186 3.22 ± 0.72 547 3.55 ± 0.79 < .0001  
 Post-bronchodilator FEV1/FVC 186 0.58 ± 0.09 547 0.48 ± 0.11 < .0001  
 BDR, bronchodilator response 186 7.47 ± 13.49 546 10.23 ± 10.45 0.0116  
Chest CT measurement       
 Mean wall area (%) 181 68.58 ± 4.79 516 66.05 ± 4.95 < .0001 < .001
 Emphysema index 182 9.28 ± 7.75 516 19.64 ± 14.55 < .0001 < .001
 Mean lung density 99 0.95 ± 0.04 516 0.94 ± 0.04 0.1075 0.116
Biomarkers       
 WBC (× 103/μl) 185 6.95 ± 1.85 448 7.31 ± 2.02 0.0394 0.028
 RBC (× 106/μl) 185 4.54 ± 0.47 449 4.70 ± 0.45 < .0001 < .001
 Hemoglobin (g/dL) 185 14.32 ± 1.48 451 14.74 ± 1.38 0.0008 0.001
 Hematocrit (g/dL) 185 41.74 ± 4.04 449 43.80 ± 3.86 < .0001 < .001
 Eosinophil (%) 185 2.98 ± 3.45 443 3.67 ± 3.24 0.0185 0.012
 Lymphocyte (%) 185 30.80 ± 8.03 443 31.19 ± 8.67 0.5988 0.932
 Neutrophil (%) 185 57.74 ± 8.97 439 57.16 ± 9.64 0.4894 0.411
 Neutrophil/lymphocyte 185 2.11 ± 1.00 439 2.21 ± 2.22 0.4242 0.744
 hs-CRP (mg/dL) 169 0.29 ± 0.59 299 0.39 ± 1.01 0.1630 < .001
  1. Data are presented as mean ± standard deviation for continuous variables or number (%) for categorical variables
  2. Statistical differences between the two groups were estimated by independent sample t-test for parametric values and Mann–Whitney U-test for non-parametric values after log-transformation, or chi-square test for categorical variables
  3. Subject criterion: COPD (post FEV1/FVC < 0.7) and pack-year ≥ 10
  4. BDR was calculated as follows: FEV1(L) post-bronchodilator minus FEV1(L) pre-bronchodilator / FEV1(L) pre-bronchodilator × 100%
  5. BMI body mass index, CT computed tomography, BDR bronchodilator response, FEV1 forced expiratory volume in 1 s, FVC forced vital capacity, CAT COPD assessment test, WBC white blood cell, RBC red blood cell, hs-CRP high-sensitivity c-reactive protein
  6. *COPD medication includes LAMA, LABA, SABA, or ICS/LABA
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