Table 5.

NEC incidence in early-antibiotic group compared with the no-early-antibiotic group in different geographic regions

	5 GD NICUs			8 non-GD NICUs			6 western NICUs
Model1	Odds ratio	95% CI	P value	Odds ratio	95% CI	P value	Odds ratio	95% CI	P value
A	0.22	0.09-0.51	<0.001	0.82	0.45-1.49	0.49	0.96	0.52-1.80	0.91
B	0.14	0.05-0.35	<0.000	0.34	0.17-0.69	<0.01	0.39	0.19-0.81	<0.05
C	0.13	0.05-0.34	<0.000	0.32	0.15-0.70	<0.01	0.38	0.17-0.87	<0.05
D	0.11	0.04-0.32	<0.000	0.33	0.15-0.72	<0.01	0.39	0.17-0.89	<0.05

¹Adjustment of models: Model A, NICU as the random effect and no adjustment for other fixed-effect; model B, model A with adjustment for gestational age, birth weight, and gender as fixed-effects; model C, model B with additional adjustment for delivery model, use of antenatal steroids, and Apgar score at 5 min; model D, model C with additional adjustment for initiation time of enteral nutrition and type of enteral nutrition in the first week of life. GD, Guangdong province in China; NICU, neonatal intensive care units