Table 1.

General characteristics and laboratory investigation of studied groups.

Studied groups	Cases (n = 27)	Control (n = 21)	Test of significance and P-value
Age (yr, mean ± SD)	9 ± 2.2	8.1 ± 3	t-test = 3.3, P = 0.8
Gender (male/female) n (%)	17/10 (63/37)	11/10 (52.4/46.8)	χ2 = 0.5, P = 0.5
Residence n (%)			χ2 = 9, P = 0.007
Urban	17 (63.0)	21 (100.0%)
Suburban	6 (22.2)	0
Rural	4 (14.8)	0
Eosinophils (%, mean ± SD)	4 ± 2.8	1.5 ± 0.3	t-test = 3.7, P = 0.001
IL-13 (pg/ml, mean ± SD)	20.4 ± 6	2.3 ± 0.6	t-test = 13, P < 0.05
FEV1 % of asthma cases Mean ± SD	83 ± 10	- - - - - - -	- - - - - - - - - - -

FEV1: forced expiratory volume in the first second.