TABLE 3.

Bivariable and Multivariable Regression of Antibiotic Initiation and Duration and Low-Risk Delivery Characteristics Among Infants Without Early-Onset Sepsis

	Low-Risk		Not Low-Risk		Low-Risk Compared to Not Low-Risk
	n	%	n	%	OR (95% CI)	P	aOR (95% CI)d	P
Antibiotic initiationa	901	80.4	5812	91.0	0.4 (0.3, 0.5)	<.001	0.5 (0.4, 0.6)	<.001
Prolonged antibioticsb,c	203	22.5	1038	17.9	1.3 (1.1, 1.6)	.001	1.1 (0.9, 1.3)
	Median	IQR	Median	IQR	Unadjusted difference (95% CI)	P	Adjusted difference (95% CI)e	P
Antibiotic duration (hours)b	47	37–62	38	37–51	9.3 (4.8, 13.8)	<.001	0.6 (−3.8, 5.1)	.79

aOR, adjusted odds ratio; CI, confidence interval; IQR, interquartile range; OR, odds ratio.

^aIncludes infants who did not have early-onset sepsis (n = 7508).

^bIncludes infants started on antibiotics in first 72 h after birth who did not have early-onset sepsis (n = 6713).

^cProlonged antibiotics defined as antibiotics continued for more than 72 h after initiation.

^dLogistic regression (complete case) adjusted for center, gestational age, sex, 5-min Apgar, maternal race/ethnicity, and maternal age.

^eLinear regression (complete case) adjusted for center, gestational age, sex, 5-min Apgar, maternal race/ethnicity, and maternal age.