Table 2.

Medical and Neurologic Complications by Group

	BPD			VLBW			χ ²	p
	Mean	SD	%	Mean	SD	%	χ ²	p
Minor neurologic malformations			1			1	0.1	1.00
Seizures			7			0	5.7	.02
Porencephaly			3			4	0.0	1.00
Hydrocephalus			9			5	1.3	.28
Ventriculoperitoneal shunt			3			1	0.4	.64
shunt
Meningitis			2			0	1.4	.51
Intraventricular hemorrhage			43			18	13.9	.01
Grades I–II			28			14	5.3	.02
Grades III–IV			15			4	6.8	.01
Periventricular leukomalacia			8			7	0.2	.78
Neurologic risk score^a	1.3	2		.58	1		3.34^b	.001
Necrotizing enterocolitis			4			6	.4	.74
Retinopathy of prematurity			43			4	39.2	.001
Patent ductus arteriosis			56			18	29.7	.001
Hearing abnormal			16			11	.7	.52
Peak bilirubin	8.3	3		9.1	3		1.8^b	.05
Septicemia			47			24	11.2	.001

BPD, bronchopulmonary dysplasia; VLBW, very low birth weight.

Neurologic risk score is a summary variable, calculated by summarizing the number of zeros and ones, where zero was used for absence and one for presence of the above listed neurological risk factors. The neurological risk score could range from 0–8 for an individual infant.

t value.