Table 1. Baseline characteristics of the study participants stratified by children who had current asthma during the study period and children who did not [n (%)].

Characteristic	Children with asthma (n = 18)	Children without asthma (n = 109)	P value*
Sex			.53
Boy	11 (61.1)	58 (53.2)
Girl	7 (38.9)	51 (46.8)
Parental asthma history			.09
No	14 (77.8)	99 (90.8)
Yes	1 (5.6)	5 (4.6)
Missing	3 (16.7)	5 (4.6)
Fetal tobacco smoke exposure†			.94
No	15 (83.3)	90 (82.6)
Yes	22 (16.7)	19 (17.4)
Environmental tobacco smoke exposure§			.50
No	12 (66.7)	81 (74.3)
Yes	6 (33.3)	28 (25.7)
Pet ownership‡			.45
No	15 (83.3)	82 (75.2)
Yes	3 (16.7)	27 (24.8)
Breast-fed			.11
No	5 (27.8)	35 (32.1)
<3 months	4 (22.2)	18 (16.5)
3–5 months	0 (0)	16 (14.7)
≥6months	4 (22.2)	30 (27.5)
Did not answer	5 (27.8)	10 (9.2)
Cockroach sensitization			.67
No	17 (94.4)	103 (94.5)
Yes	0 (0)	3 (2.8)
Did not answer	1 (5.6)	3 (2.8)
Maternal education			.67
< High school	3 (11.9)	13 (11.9)
High school	7 (38.9)	51 (46.8)
>High school	5 (27.8)	34 (31.2)
Did not answer	3 (16.7)	11 (10.1)
Paternal education			.19
< High school	3 (16.7)	6 (5.5)
High school	6 (33.3)	50 (45.9)
>High school	6 (33.3)	43 (33.3)
Did not answer	3 (16.7)	3 (9.2)

* P value was estimated based on Chi-square test or Fisher’s exact test.

^†Active maternal smoking during pregnancy or presence of a smoker in the home during pregnancy.

^‡Active maternal smoking during the first year after delivery, current maternal smoking, or presence of a smoker in the home after delivery until the present time.

^§Having had a pet dog or cat after delivery until the present time.

Size of the wheal produced by the cockroach antigen ≥3 mm and larger than size of the wheal produced by histamine.