Study population at follow-up in a longitudinal study between 1989–2001 of adult subjects with asthma from northern Europe
| Predictor | |
| Total subjects | 1153 |
| Subjects born after 1959 | 586 (50.8) |
| Subjects born 1945–1959 | 567 (49.2) |
| Female | 693 (60.1) |
| Male | 460 (39.9) |
| Never-smokers at follow-up | 507 (44.0) |
| Former smokers at follow-up | 305 (26.4) |
| Current smokers at follow-up | 323 (28.0) |
| Unknown smoking habits | 18 (1.6) |
| Allergic rhinitis at baseline | 606 (52.6) |
| Wheezing in the last 12 months at baseline | 730 (63.3) |
| Nocturnal cough in the last 12 months at baseline | 481 (41.7) |
| Nocturnal chest tightness in the last 12 months at baseline | 382 (33.1) |
| Nocturnal dyspnoea in the last 12 months at baseline | 257 (22.3) |
| Any attacks of asthma in the last 12 months at baseline | 349 (30.7) |
| Any asthma symptom in the last 12 months at baseline# | 903 (78.3) |
Data are presented as n or n (%). #: wheezing, asthma attacks or nocturnal cough, chest tightness or dyspnoea in the last 12 months.