(c).

		BPD
	Odds ratio	95% confidence interval		p value
		Lower	Upper
Initiation timing of caffeine therapy	0.393	0.126	1.223	0.107
GA (wks)	0.878	0.642	1.202	0.416
BW (g)	0.996	0.993	0.999	0.018∗
		PDA requiring ligation
	Odds ratio	95% confidence interval		p value
		Lower	Upper
Initiation timing of caffeine therapy	0.473	0.075	2.967	0.424
GA (wks)	0.842	0.467	1.518	0.567
BW (g)	0.997	0.991	1.004	0.404

(∗) means statistically significant.

DOL, days of life; BPD, bronchopulmonary dysplasia; PDA, patent ductus arteriosus; GA, gestational week; BW, birthweight.