Table 3.

Result of multiple logistic regression. Variables that remained in the final model with significance.

Variables	p-value a	OD ratio (95%)
Nutritional supplementation (iron)	0.007	0.22 (0.07‒0.66)
Vitamin and ferrous sulfate supplementation	<0.001	0.03 (0.08‒0.17)
Second-hand tobacco smoke > 15 min	<0.001	5.62 (3.26‒9.67)

^aMultivariate logistic regression.