TABLE 2.

Odds ratios for factors associated with low IP adjusted for postmenstrual age and birth weight^a

Factor	OR	95% CI for OR	P value for ORd	Adjusted ORc	95% CI for adjusted OR	P value for adjusted ORd
Duration of antibiotic useb
≤3 days	2.65	1.12, 6.25	0.02	1.56	0.58, 4.16	0.37
>3 days	1.0 (ref)			1.0 (ref)
Duration of MOM feedingb
≥4 days	7.04	2.5, 19.6	<0.01	10.30	3.21, 33.33	<0.01
<4 days	1.0 (ref)			1.0 (ref)

^aFisher’s exact test was used to calculate P values for categorical variables. Student’s t test was used for continuous variables (birth weight, gestational age [GA], postmenstrual age [PMA], and APGAR scores at 1 min and 5 min). Intestinal permeability (IP) was calculated as the ratio of urine lactulose (La) to rhamnose (Rh), and an La/Rh ratio of <0.05 was defined as low IP. MOM, mother’s own breastmilk; OR, odds ratio; CI, confidence interval.

^bVariable measured during the time period starting from the enrollment day (within 1 to 4 days after birth depending on clinical stability) until the day when IP was measured (day 8 ± 2 after birth).

^cThe adjusted OR model includes PMA and birth weight.

^dP value calculated using logistic regression.