Subgroups according to increasing number of predisposing factors | No* | No (%) with hay fever | OR (95% CI)†per sibling | p value |
---|---|---|---|---|
*Of 18 530 subjects who provided questionnaire information, 13 932 provided blood tests for IgE analyses and some data are missing for each variable. Thus, the totals of the individual rows does not equal the final total. | ||||
†Estimated by logistic regression adjusted for number of siblings, bedroom sharing, serious respiratory infections, sex, age, current smoking, current occupation, and centre. | ||||
No atopy, no parental allergy | 6852 | 839 (12%) | 1.02 (0.97 to 1.09) | NS |
No atopy, parental allergy | 2508 | 603 (24%) | 0.91 (0.84 to 0.99) | 0.028 |
Atopy, no parental allergy | 2908 | 1176 (40%) | 0.92 (0.86 to 0.98) | 0.007 |
Atopy, parental allergy | 1581 | 1021 (64%) | 0.88 (0.80 to 0.96) | 0.006 |
All | 17676 | 4840 (27%) | 0.92 (0.90 to 0.95) | <0.001 |