Table 1. Characteristics of patients according to IVH/non-IVH group.
Statistical significance was set at p<0.05.
t, t-test; U, Mann-Whitney U statistic; Z, standardized test statistic for the Mann-Whitney U test; χ², Chi-square test; Fisher's, Fisher's exact test; RDS, respiratory distress syndrome; MV, mechanical ventilation; PDA, patent ductus arteriosus; IVH, intraventricular hemorrhage
| Characteristics | IVH | Non-IVH | Test | P-value |
| Gestational age (weeks) characteristics | 28.0±2.5 | 30.1±2.0 | t=5.74 | <0.001 |
| Birth weight (mean, grams) | 1181.5 | 1527.6 | U=1451.0, Z=-4.723 | <0.001 |
| Apgar 1st min | 5.8 | 6.8 | t=2.725 | 0.004 |
| Apgar 5th min | 7.8 | 7 | t=2.710 | 0.006 |
| RDS (%) | 81.1% | 60.6% | χ²(1)=6.764 | 0.009 |
| MV<3 days (%) | 24.1% | 75.9% | χ²(1)=11.56 | <0.001 |
| MV<3 days (%) | 54.5% | 45.5% | ||
| Inotrope (%) | 35.8% | 8.7% | χ²(1)=17.72 | <0.001 |
| PDA (%) | 85.7% | 14.3% | Fisher's | <0.001 |
| Died (%) | 83.3% | 16.7% | χ²(1)=31.14 | <0.001 |