Characteristics of participants in the European Community Respiratory Health Survey(ECRHS) and Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA) at baseline
| Both cohorts | ECRHS | SAPALDIA | |||
| Symptom sample | Random sample | Age 18–44 yrs | All ages | ||
| Subjects n | 10736 | 796 | 3869 | 3572 | 6071 |
| Males % | 49 | 44 | 48 | 50 | 50 |
| Age yrs | 38±10 | 34±7 | 34±7 | 33±8 | 41±11 |
| BMI kg·m−2 | 23.9±3.8 | 25.1±4.8 | 23.9±3.7 | 23.1±3.4 | 23.8±3.6 |
| Smoking status % | |||||
| Never-smoker | 45.5 | 42.7 | 43.5 | 48.0 | 47.1 |
| Ex-smoker | 22.4 | 18.6 | 21.7 | 19.6 | 23.3 |
| Current smoker | 32.1 | 38.7 | 34.7 | 32.5 | 29.6 |
| Asthma symptoms % | 5.6 | 35.8 | 3.7 | 2.9 | 2.9 |
| Physician-diagnosed asthma % | 8.8 | 38.7 | 6.7 | 6.2 | 6.2 |
| Atopy % | 21.5 | 48.4 | 24.7 | 22.9 | 19.8 |
| FEV1 % pred | 106.6±14.6 | 100.3±16.4 | 105.8±13.3 | 107.1±13.4 | 107.8±14.9 |
| FVC % pred | 112.3±14.9 | 107.4±14.3 | 109.2±13.1 | 112.3±13.9 | 114.9±15.5 |
| BHR % | 12.5 | 37.8 | 11.7 | 9.2 | 9.9 |
Data are presented as mean±sd unless otherwise indicated. BMI: body mass index; FEV1: forced expiratory volume in one second; FVC: forced vital capacity; BHR: bronchial hyperresponsiveness; % pred: % predicted.