. 2016 Feb 22;31(4):579–584. doi: 10.3346/jkms.2016.31.4.579

Table 2. Multiple linear regression analysis for the infant mental development index score and covariates according to breastfeeding duration after adjustment*.

Cognitive development	Independent variable	β	95% CI	P	R²(P)
12 mon of age	Duration of breastfeeding	0.39	0.13-0.64	0.003	0.066 (< 0.001)
12 mon of age	Sex (female vs. male)	4.89	2.43-7.34	< 0.001	0.066 (< 0.001)
24 mon of age	Duration of breastfeeding	0.40	0.14-0.66	0.003	0.105 (< 0.001)
24 mon of age	Sex (female vs. male)	7.68	5.15-10.21	< 0.001	0.105 (< 0.001)
36 mon of age	Duration of breastfeeding	0.37	0.08-0.66	0.013	0.101 (< 0.001)
36 mon of age	Sex (female vs. male)	7.19	4.38-10.00	< 0.001	0.101 (< 0.001)

*Covariates included maternal age, educational level of mother, family income, gestational age and birth weight. CI, confidence interval.