Demographic details of study population and distribution of background variables in children of atopic and non-atopic parents
| Variables | Children of atopic parents (n=270) | Children of non-atopic parents (n=232) | p value |
|---|---|---|---|
| Gender male, % | 51.7 | 46.7 | NS |
| Mean age in years (SD) | 12.7 (2.5) | 12.7 (2.6) | NS |
| Skin prick test positive, % | 49.3 | 31.9 | <0.001 |
| Breast feeding, % | 96.2 | 92.1 | NS |
| Mothers smoking during infancy, % | 24.4 | 30.2 | NS |
| Mothers smoking during pregnancy, % | 32.6 | 34.9 | NS |
| Day care attendance, % | 11.1 | 8.6 | NS |
| Group 1 (asthma) | 104 (62.7%) | 62 (37.5%) | <0.001 |
| Group 2 (wheeze) | 95 (61.3%) | 60 (38.7%) | <0.001 |
| Group 3 (no asthma/no wheeze) | 71 (39.2%) | 110 (60.8%) | <0.001 |
| Area | |||
| Oslo | 106 | 80 | NS |
| Hallingdal | 108 | 102 | NS |
| Odda | 56 | 50 | NS |