Table 2.

Results of the univariate survival analysis

Variable	Quartiles					Corrected P value	Coefficient	Exponentiated Coefficient (95% CI)	Risk change for 75% Quartile
	0%	25%	50%	75%	100%
Gestation (days)	161	184	198	211	223	0.002	0.026	1.026 (1.013–1.040)	3.688
Birth weight (g)	500	800	1025	1325	1890	< 0.001	0.001	1.001 (1.001–1.002)	2.788
Days of mechanical ventilation	0	0	1	2	84	0.021	−0.076	0.927 (0.885–0.971)	0.860
Days of CPAP oxygen	0	0	2	12	80	< 0.001	−0.039	0.962 (0.947–0.977)	0.626
Days of maternal milk feeds (non-breast)	0	6	14	29	114	< 0.001	−0.057	0.945 (0.930–0.959)	0.192
Days of breast feeds	0	0	0	3	48	0.001	−0.073	0.929 (0.896–0.964)	0.802
Days of antibiotic use	0	2	3	6	79	< 0.001	−0.116	0.89 (0.848–0.934)	0.497