Table 1.
Characteristics1) of the study populations and genotype distribution.
| ECRHS-Basel N = 418 (%) | SAPALDIA N = 6003 (%) | |
| Female proportion | 211 (50.5) | 3022 (50.3) |
| Age [years] | 43.4 (± 7.0) | 41.3 (± 11.4) |
| Age range [years] | 29.3 to 55.1 | 18.2 to 61.8 |
| Hay fever cases2) | 192 (45.9) | 1105 (18.4) |
| Asthma cases3) | 78 (18.2) | 369 (6.2) |
| Eczema cases4) | 200 (47.9) | 2383 (39.7) |
| Elevated total IgE cases5) | 101 (24.9) | 1168 (21.6) |
| Allergen sensitization cases6) | 178 (42.6) | 1620 (29.1) |
| Non-atopic controls7) | 125 (29.9) | 2953 (49.2) |
1) Presented in N (%) for categorical and in mean (± SD) for continuous variables.
2) Self-reported hay fever cases answered yes to, Have you ever had a problem with sneezing or a runny nose or a blocked nose when you did not have a cold?', irrespective of self-reported asthma or eczema.
3) Physician-diagnosed asthma cases answered twice yes to 'Have you ever had asthma? Was this confirmed by a doctor?', irrespective of self-reported hay fever or eczema.
4) Self-reported eczema cases answered yes to 'Have you ever had eczema or any other kind of skin allergy?', irrespective of self-reported asthma or hay fever.
5) Elevated total IgE cases had serum total IgE level >100 kU/L, measured by CAP system (Pharmacia)
6) Allergen sensitization cases had at least one allergen specific IgE >0.35 kU/L, measured by CAP system (Pharmacia) for ECRHS-BS and by Phadiatop test (CAP FEIA system, Pharmacia) for SAPALDIA.
7) Non-atopic controls were free of self-reported hay fever, self-reported eczema and physician-diagnosed asthma.