Adjusted odds ratios (95% CI) of respiratory symptoms and COPD associated with COE exposure using control group as a referent
| Control group(n = 211) | Low exposure(n = 238) | Moderate exposure(n = 237) | High exposure(n = 237) | |
|---|---|---|---|---|
| *Number (%). | ||||
| †Adjusted for sex, age (<30, 30–34, 35–39, and ⩾40 years), height (<164, 164–167, 168–171, and ⩾172 cm), and cigarette-years of smoking (0, 1–99, 100–199, 200–299 and ⩾300 μg/m3-years) by logistic regression. | ||||
| Number and prevalence* | ||||
| Chronic cough or chronic phlegm | 29 (13.7) | 50 (21.0) | 62 (26.2) | 82 (34.6) |
| COPD | 15 (7.1) | 29 (12.2) | 56 (23.6) | 71 (30.0) |
| Mild | 4 (1.9) | 7 (2.9) | 5 (2.1) | 3 (1.3) |
| Moderate | 8 (3.8) | 18 (7.6) | 41 (17.3) | 58 (24.5) |
| Severe | 3 (1.4) | 3 (1.3) | 10 (4.2) | 9 (3.8) |
| Very severe | 0 (0.0) | 1 (0.4) | 0 (0.0) | 1 (0.4) |
| Adjusted OR (95% CI)† | ||||
| Chronic cough or chronic phlegm | 1 (referent) | 1.60 (0.97 to 2.65) | 1.99 (1.21 to 3.26) | 3.10 (1.91 to 5.03) |
| COPD | 1 (referent) | 1.68 (0.86 to 3.27) | 3.21 (1.71 to 6.01) | 5.80 (3.13 to 10.76) |
| Mild | 1 (referent) | 1.74 (0.49 to 6.20) | 1.27 (0.31 to 5.14) | 0.77 (0.16 to 3.60) |
| Moderate | 1 (referent) | 1.89 (0.80 to 4.47) | 4.00 (1.80 to 8.89) | 8.22 (3.76 to 17.97) |
| Severe or very severe | 1 (referent) | 1.03 (0.22 to 4.80) | 2.26 (0.57 to 8.93) | 2.75 (0.71 to 10.66) |