Comparison between the training and validation groups
| Training Group | Validation group | p Value | |
|---|---|---|---|
| (n=2015) (%) | (n=2015) (%) | ||
| Gestational age (weeks) | |||
| 22–26 | 4.4 | 4.7 | 0.24 |
| 27–28 | 9.1 | 8.6 | |
| 29–30 | 15.6 | 13.3 | |
| 31–32 | 24.2 | 25.9 | |
| 33–34 | 46.7 | 47.4 | |
| Birthweight (g) | |||
| 450–999 | 12.2 | 12.8 | 0.96 |
| 1000–1499 | 25.5 | 25.1 | |
| 1500–1999 | 36.1 | 36.2 | |
| ≥2000 | 26.2 | 25.9 | |
| Male | 53.6 | 54.6 | 0.45 |
| Birth year | |||
| 2003–2004 | 30.0 | 30.5 | 0.62 |
| 2005–2006 | 34.6 | 33.2 | |
| 2007–2008 | 35.6 | 36.3 | |
| Cranial ultrasound/MRI abnormalities | |||
| No cranial ultrasound, no MRI | 23.8 | 22.2 | 0.13 |
| No lesion on cranial ultrasound and/or MRI | 68.4 | 71.1 | |
| Intraventricular haemorrhage (grade II) | 3.5 | 3.5 | |
| Severe cranial ultrasound/MRI abnormalities | 4.2 | 3.2 | |
| Intraventricular haemorrhage (grades III and IV) | 0.6 | 0.3 | |
| White matter damage | 3.5 | 2.6 | |
| White matter damage and intraventricular haemorrhage | 0.1 | 0.3 | |
| Outcome at 2 years | |||
| Not examined at 2 years | 15.9 | 17.6 | 0.71 |
| Death after discharge | 0.1 | 0.1 | |
| Genetic syndrome | 0.7 | 0.7 | |
| Optimal neuromotor development | 74.2 | 73.0 | |
| Suboptimal neuromotor development | 8.9 | 8.7 | |
| Cerebral palsy without independent walking | 1.6 | 2.1 | |
| Cerebral palsy with independent walking | 3.8 | 4.2 | |
| Gross and/or fine motor domain impairment (ASQ) | 3.5 | 2.4 |
ASQ, ages and stages questionnaires.