Table 4 Adjusted ORs of respiratory symptoms and COPD associated with cigarette smoking.
| Cigarette‐years of smoking | |||||
|---|---|---|---|---|---|
| Never (n = 268) | 1–99 (n = 210) | 100–199 (n = 137) | 200–299 (n = 120) | ⩾300 (n = 188) | |
| Number and prevalence* | |||||
| Chronic cough or chronic phlegm | 57 (21.3) | 36 (17.1) | 29 (21.2) | 37 (30.8) | 64 (34.0) |
| COPD | 25 (9.3) | 24 (11.4) | 26 (19.0) | 29 (24.2) | 67 (35.6) |
| Mild | 5 (1.9) | 3 (1.4) | 4 (2.9) | 1 (0.8) | 6 (3.2) |
| Moderate | 18 (6.7) | 21 (10.0) | 14 (10.2) | 24 (20.0) | 48 (25.5) |
| Severe | 2 (0.7) | 0 (0.0) | 8 (5.8) | 4 (3.3) | 11 (5.9) |
| Very severe | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 ( (0.0) | 2 (1.1) |
| Adjusted OR (95% CI)† | |||||
| Chronic cough or chronic phlegm | 1 (referent) | 0.77 (0.48 to 1.24) | 0.99 (0.58 to 1.66) | 1.73 (1.03 to 2.91) | 1.93 (1.19 to 3.13) |
| COPD | 1 (referent) | 1.46 (0.78 to 2.72) | 2.40 (1.28 to 4.51) | 3.25 (1.72 to 6.15) | 5.26 (2.90 to 9.53) |
| Mild | 1 (referent) | 1.23 (0.27 to 5.67) | 2.23 (0.53 to 9.37) | 0.48 (0.05 to 4.52) | 2.25 (0.52 to 9.67) |
| Moderate | 1 (referent) | 1.59 (0.80 to 3.16) | 1.43 (0.67 to 3.05) | 3.28 (1.62 to 6.64) | 4.16 (2.14 to 8.09) |
| Severe or very severe | 1 (referent) | – | 10.47 (1.99 to 55.04) | 5.72 (0.92 to 35.49) | 11.92 (2.14 to 66.31) |
*Number (%).
†Adjusted for sex, age (<30, 30–34, 35–39, and ⩾40 years), height (<164, 164–167, 168–171, and ⩾172 cm), and cumulative COE exposure levels (0, <630, 630–1713, and ⩾1714 μg/m3‐years) by logistic regression.