Table 5. Multivariable analysis between wheeze and covariates in the three age groups.

		3 month group			18 month group			36 month group
		aOR	95%CI	P	aOR	95%CI	P	aOR	95%CI	P
Gender
	Female	reference	―	―	reference	―	―	reference	―	―
	Male	1.51	1.40–1.63	<0.001	1.43	1.36–1.52	<0.001	1.37	1.29–1.46	<0.001
Birth season
	Spring (Mar. to May)	reference	―	―	reference	―	―	reference	―	―
	Summer (Jun. to Aug.)	1.22	1.10–1.36	<0.001	0.85	0.79–0.92	<0.001	1.00	0.92–1.10	0.945
	Autumn (Sep. to Nov.)	1.09	0.98–1.22	0.103	0.82	0.76–0.88	<0.001	1.23	1.12–1.34	<0.001
	Winter (Dec. to Feb.)	0.91	0.81–1.02	0.093	0.81	0.75–0.87	<0.001	1.14	1.04–1.25	0.004
Birth order
	First	reference	―	―	reference	―	―	reference	―	―
	Second and after	1.22	1.13–1.32	<0.001	1.06	1.00–1.12	0.042	0.98	0.92–1.04	0.427
Paternal bronchial asthma
	No	reference	―	―	reference	―	―	reference	―	―
	Yes	1.41	1.25–1.60	<0.001	1.71	1.56–1.87	<0.001	2.33	2.11–2.56	<0.001
Maternal bronchial asthma
	No	reference	―	―	reference	―	―	reference	―	―
	Yes	1.74	1.55–1.95	<0.001	2.12	1.94–2.32	<0.001	2.75	2.51–3.01	<0.001