Incidence of COPD stage 1, 2, and 3–4 among men participating in all four examinations from 1976 to 2004
| N at baseline | No COPD | COPD stage 1 | COPD stage 2 | COPD stage 3–4 | |
|---|---|---|---|---|---|
| Data are shown as n (%). | |||||
| Never smokers | 141 | 135 (96) | 5 (3) | 1 (1) | 0 (0) |
| Ex-smokers | 162 | 143 (88) | 7 (5) | 10 (7) | 2 (1) |
| Early cessation | 42 | 40 (95) | 1 (2.5) | 1 (2.5) | 0 (0) |
| Intermediary cessation | 81 | 70 (86) | 0 (0) | 9 (11) | 2 (3) |
| Late cessation | 94 | 71 (76) | 9 (9.5) | 9 (9.5) | 5 (5) |
| Continuous smokers | 256 | 150 (59) | 36 (14) | 56 (22) | 14 (5) |