Table 2. Prevalence of allergic disease, airway hyperresponsiveness, and allergic sensitization of the study subjects.

	Total		Study region (%)
	n/N	%	Metropolitans	Industrial area	Rural area	P value
Wheeze, ever	1,000/4,203	23.8	24.5	23.6	23.4	0.792
Wheeze, past year	522/4,203	12.4	10.7	12.7	13.3	0.109
Diagnosed asthma, ever	466/4,203	11.1	11.9	10.3	11.3	0.401
Asthma treatment, past year	184/4,203	4.4	4.0	4.3	4.7	0.627
Allergic rhinitis symptoms, ever	1,943/4,167	46.6	47.6	46.9	45.7	0.621
Allergic rhinitis symptoms, past year	1,734/4,167	41.6	43.3	42.2	39.9	0.181
Diagnosed allergic rhinitis, ever	1,076/4,167	25.8	28.8	28.6	21.0	<0.001
Allergic rhinitis treatment, past year	858/4,167	20.6	23.1	23.3	16.1	<0.001
Airway hyperresponsiveness
PC20≤8 mg/mL	389/1,855	21.0	27.7	16.8	18.2	<0.001
Allergic sensitization
Any allergen positive	420/1,254	33.5	36.7	33.6	29.7	0.129