Baseline (European Community Respiratory Health Survey (ECRHS) I) characteristics of the subjects participating in ECRHS II
| Subjects included in the analyses | Subjects not included in the analyses | p-value | |
| Subjects | 6984 | 3949 | |
| Female | 3708 (53) | 2100 (53) | 0.93 |
| Age years | 34.3±7.1 | 33.7±7.2 | <0.001 |
| BMI kg·m−2 | 24.1±4.0 | 24.1±4.0 | 0.53 |
| Low education | 875 (13) | 499 (13) | 0.83 |
| Smoking habits | 0.16 | ||
| Nonsmoker | 3067 (45) | 1793 (46) | |
| <15 pack-years | 2499 (36) | 1347 (35) | |
| ≥15 pack-years | 1321 (19) | 722 (19) | |
| Sensitisation to allergens | 2130 (34) | 970 (35) | 0.49 |
| FEV1 % predicted | 105.0±13.5 | 105.0±15.2 | 0.95 |
| AHR | 886 (15) | 398 (18) | 0.001 |
Data are presented as n, n (%) or mean±sd, unless otherwise stated. BMI: body mass index; FEV1: forced expiratory volume in 1 s; AHR: airway hyperresponsiveness.