Respiratory health characteristics of the study population stratified by survey (n=6443)
| ECRHS I | ECRHS II | |
| n (%) | n (%) | |
| Smoking status | ||
| Never | 2844 (44.1) | 2681 (41.6) |
| Ex | 1392 (21.6) | 1828 (28.4) |
| Current | 2203 (34.2) | 1876 (29.1) |
| Ever asthma | 479 (7.4) | 713 (11.1) |
| Asthma medication | 153 (2.4) | 243 (3.8) |
| Chronic bronchitis | 185 (3.1) | 178 (3.0) |
| Atopy* | 1686 (29.1) | 1680 (28.3) |
| Mean (SD) | Mean (SD) | |
| FEV1 (l/s) | 3.8 (0.8) | 3.5 (0.8) |
| Age (years) | 34.2 (7.1) | 43.0 (7.1) |
| BMI (kg/m2) | 23.9 (3.8) | 25.5 (4.4) |
↵* At least one specific IgE level (cat, timothy grass, Cladosporium herbarium Dermatophagoides pteronyssinus) >0.35 kU/l.
BMI, body mass index; ECHRS, European Community Respiratory Health Survey; FEV1, forced expiratory volume in 1 s; IgE, immunoglobulin E.