| Year of Entry | Calendar Period (subjects with known outcome) |
| 1983 | 1988 | 1993 | 1983/1988 | 1988/1993 | 1993/1998 |
Subjects n | 628 | 309 | 628 | 612 | 730 | 737 |
Male % | 49.4 | 54.7 | 49.8 | 49.3 | 50.7 | 49.2 |
Age yrs | 52 (16) | 50 (17) | 53 (16) | 52 (16) | 50 (17) | 53 (16) |
Duration yrs | 19.5 (16.2) | 15.3 (14.7) | 18.1 (16.9) | 19.5 (16.2) | 20.7 (16.1) | 23.3 (16.2) |
Atopic % | 53.7 | 52.4 | 47.9 | 53.6 | 50.6 | 45.4 |
Current smoker % | 15.6 | 14.9 | 14.9 | 15.8 | 12.0 | 9.2 |
Amount smoked pack-yrs# | 13.0 (20.1) | 15.5 (22.0) | 15.2 (21.1) | 13.0 (20.1) | 13.9 (20.7) | 12.5 (20.1) |
Actual FEV1 | 75.0 (27.1) | 78.6 (28.1) | 77.0 (26.7) | 75.2 (27.1) | 76.4 (27.3) | 75.3 (26.8) |
Best FEV1 | n.a. | 77.0 (26.7) | 87.6 (33.1) | n.a. | 84.6 (27.2) | 84.6 (27.2) |
Best FVC¶ + | 96.2 (19.4) | 94.8 (23.5) | 94.8 (25.5) | 96.3 (19.7) | 94.0 (22.9)§ | 93.4 (22.3)f |
Actual/best PEF | 79.6 (16.7) | 86.4 (13.5) | 88.2 (11.2) | 79.6 (16.7) | 85.1 (14.0) | 86.9 (12.2) |