Characteristics of population (includes cases and subjects from the comparison group and cases)
| Variable | Total population (n = 4331) | Population in this analysis (n = 2474) |
| Country | ||
| Australia | 341 (7.9%) | 239 (9.7%) |
| France | 549 (12.7%) | 330 (13.3%) |
| Germany | 439 (10.1%) | 256 (10.3%) |
| Norway | 436 (10.1%) | 254 (10.3%) |
| Spain | 1165 (26.9%) | 571 (23.1%) |
| Sweden | 643 (14.8%) | 414 (16.7%) |
| Switzerland | 400 (9.2%) | 202 (8.2%) |
| UK | 358 (8.3%) | 208 (8.4%) |
| Sex | ||
| Men | 2089 (48.2%) | 1271 (51.4%) |
| Women | 2242 (51.8%) | 1203 (48.6%) |
| Smoking | ||
| Never | 1855 (42.8%) | 1124 (45.4%) |
| Ex | 1144 (26.4%) | 670 (27.1%) |
| Current | 1348 (31.1%) | 692 (28%) |
| Mean (SD) age (years) | 42.8 (7.2) | 42.4 (7.1) |
| Comparison group | 1213 (28%) | 1213 (49%) |
| Asthma | 320 (7.4%) | 320 (12.9%) |
| Atopy | 1060 (24.5%) | 1060 (42.8%) |
| Atopic asthma | 195 (4.5%) | 195 (7.9%) |
| Non-atopic asthma | 55 (1.3%) | 55 (2.2%) |
| Atopy in non-asthmatics | 865 (20%) | 865 (35%) |
| BHR | 267 (6.2%) | 267 (10.8%) |
| Other* | 1307 (30.2%) | 422 (17.1%) |
↵* Subjects who reported any of the outcomes examined or other respiratory symptoms in either of the surveys, but not in both.
BHR, bronchial hyper-responsiveness.