Table 1.

Descriptive Characteristics of the Study Population (N = 1085)

	Overall	Study 1	Study 2
Number of subjects	1085	682	403
Females (%)	61	65	55**
Asthma age-of-onset < 6 (%)	31	27	38***
Family history of allergic disease (%)	81	76	92***
Eczema (%)	34	32	38*
Hayfever (%)	64	55	77***
Atopy (%), N = 402	81	81	81
FEV1 < 80% predicted (%)a, N = 468	19	19	19
Mean log total serum IgE (range), N = 444	4.7 (0.7–8.4)	4.4 (0.7–7.6)	4.9 (1.6–8.4)**

FEV₁, Forced expiratory volume after 1 second; IgE, Immunoglobulin E.

Significant difference in frequency or mean when compared to Study 1:

^*P < 0.05;

^**P < 0.005;

^***P < 0.0005.

^aPredicted FEV₁ was calculated based on each subject's age and sex.