Table 1. Logistic regression analysis of season of birth and prevalence of bronchial asthma.

Season of birth		Odds ratio (95% confidence interval)	p value
Spring (Feb.∼Apr.)	(n = 24,928)	----	----
Summer (May∼July)	(n = 24,871)	1.00 (0.92∼1.08)	0.97
Autumn (Aug.∼Oct.)	(n = 27,526)	1.13 (1.05∼1.21)	0.001 **
Winter (Nov.∼Jan.)	(n = 27,130)	1.04 (0.96∼1.12)	0.29

Adjustments were made for subject's gender, urbanization level, and geographic region.

^** p<0.01.