Demographic, clinical and functional characteristics during European Community Respiratory Health Survey I of the 815 asthmatic subjects considered in the analysis
| Females % | 56.4 |
| Age % | |
| <30 yrs | 38.8 |
| 30–40 yrs | 37.7 |
| ≥40 yrs | 23.5 |
| Smoking status % | |
| Nonsmokers | 50.8 |
| Past smokers | 20.5 |
| Current smokers | 28.7 |
| Smoking history# pack-yrs | 8.6 (3.5–16.0) |
| FEV1 % pred | 90.1±15.0 |
| FEV1 <LLN % | 23.2 |
| FVC % pred | 97.2±12.8 |
| FVC <LLN % | 9.4 |
| FEV1/FVC | 78.1±9.8 |
| FEV1/FVC <LLN % | 29.0 |
| High total IgE¶ % | 46.8 |
| IgE sensitisation+ % | 70.0 |
Data are presented as median (interquartile range) or mean±sd unless otherwise indicated. FEV1: forced expiratory volume in 1 s; % pred: % predicted; LLN: lower limit of normal; FVC: forced vital capacity; Ig: immunoglobulin. #: among past and current smokers; ¶: >100 kU·L−1; +: at least one specific IgE measurement of ≥0.35 kU·L−1 against five environmental allergens (Dermatophagoides pteronyssinus, cat, timothy grass, Cladosporium herbarum and a local allergen).