Distribution of smoking habits in both sexes by the presence of chronic bronchitis
| Smoking habits | 〈Males***〉 | 〈Females***〉 | 〈Total***〉 | |||
| With chronic bronchitis | Without chronic bronchitis | With chronic bronchitis | Without chronic bronchitis | With chronic bronchitis | Without chronic bronchitis | |
| Nonsmokers | 43 (13.4%) | 3332 (40.4%) | 55 (21.6%) | 4101 (45.7%) | 98 (17.0%) | 7433 (43.1%) |
| Past smokers | 30 (9.3%) | 1767 (21.4%) | 26 (10.2%) | 1886 (21.0%) | 56 (9.7%) | 3653 (21.2%) |
| Current smokers | 248 (77.3%) | 3148 (38.2%) | 174 (68.2%) | 2992 (33.3%) | 422 (73.3%) | 6140 (35.6%) |
| 1–14 pack-yrs | 71 (22.1%) | 1537 (18.6%) | 80 (31.4%) | 1906 (21.2%) | 151 (26.2%) | 3443 (20.0%) |
| 15–29 pack-yrs | 81 (25.2%) | 941 (11.4%) | 52 (20.4%) | 753 (8.4%) | 133 (23.1%) | 1694 (9.8%) |
| 30–44 pack-yrs | 48 (15.0%) | 297 (3.6%) | 24 (9.4%) | 175 (1.9%) | 72 (12.5%) | 472 (2.7%) |
| ≥45 pack-yrs | 33 (10.3%) | 120 (1.5%) | 9 (3.5%) | 53 (0.6%) | 42 (7.3%) | 173 (1.0%) |
| Unknown | 15 (4.7%) | 253 (3.1%) | 9 (3.5%) | 105 (1.2%) | 24 (4.2%) | 358 (2.1%) |
| Total | 321 | 8247 | 255 | 8979 | 576 | 17226 |
Data are presented as n (%). Some subjects (n=164) did not answer questions on smoking habits
***: p<0.001, the distribution of smoking habits varied significantly between subjects with and without chronic bronchitis in both sexes and in the total sample