Table 2. Multivariate Logistic Regression for Evaluation of Risk Factors for Severe Retinopathy of Prematurity.

	Model 1 (90 Days) All 684 Eyes with 76 Eyes Developing SROP			Model 2 (105 Days) 468 ROP Eyes with 76 Eyes Developing SROP			Model 3 (105 Days) 146 Prethreshold ROP Eyes with 76 Eyes Developing SROP
	Beta	Odds Ratio (95% CI)	P Value	Beta	Odds Ratio (95% CI)	P Value	Beta	Odds Ratio (95% CI)	P Value
BW (each 100 g increase)	−0.475	0.62 (0.42–0.93)	0.021	−0.416	0.66 (0.44–0.98)	0.039	−0.136	0.87 (0.58–1.32)	0.52
GA (wks)	− 0.643	0.53 (0.37–0.74)	<0.0005	−0.566	0.57 (0.40–0.81)	0.002	−0.317	0.73 (0.52–1.02)	0.067
Multiple birth (yes = 1, no = 0)	1.889	6.6 (2.3–19.3)	0.001	1.866	6.5 (2.2–18.9)	0.001	2.247	9.5 (2.4–36.7)	0.001
Race (black = 1, non-black = 0)	−1.612	0.20 (0.075–0.53)	0.001	−1.533	0.22 (0.079–0.59)	0.003	−0.774	0.32 (0.099–2.14)	0.323
Gender (male = 1, female = 0)	0.569	1.8 (0.78–3.99)	0.171	0.546	1.7 (0.75–3.98)	0.199	1.230	3.4 (1.12–10.5)	0.031
Per capita income (each $10 000)	−0.056	0.95 (0.90–0.999)	0.044	−0.057	0.94 (0.90–0.995)	0.033	−0.042	0.96 (0.89–1.03)	0.277
ADL (hours; cumulative 90 days after EDC)	−0.334	0.72 (0.55–0.94)	0.015	−0.	−0.	–	–	–	–
ADL (hours; cumulative 105 days after EDC)	–	–	–	−0.363	0.70 (0.52–0.93)	0.013	−0.624	0.54 (0.37–0.78)	0.001

ADL = average day length; BW = birth weight; CI = confidence interval; EDC = estimated date of conception; GA = gestational age; ROP = retinopathy of prematurity; SROP = severe retinopathy of prematurity.