| n | Age (y) | Gender (% female) | Pre-FEV1* (ml) | Pack-year (No) | Smoking status (% ever smokers) | |
| At risk subjects | ||||||
| Baseline group | 604 | 43.4 | 59.9 | 3058 | 9.1 | 32.0 |
| Monitoring group | 384 | 42.9 | 57.6 | 3109 | 8.9 | |
| Reassessed group (year 5) | 313 | 43.9 | 59.4 | 3065 | 8.7 | 32.6 |
| Subjects without abnormalities | ||||||
| Baseline group | 551 | 42.9 | 50.3 | 3440 | 7.0 | 37.4 |
| Reassessed group (year 5) | 151 | 42.9 | 50.3 | 3477 | 8.9 | 43.1 |
*Pre-bronchodilator forced expiratory volume.
FEV1, forced expiratory volume in 1 s.