| Trent (n = 2085) | NSW/ACT (n = 2686) | p Value orOR (95% CI) | ||
| Birth weight (g) | 1220 (910–1510) | 1230 (926–1514) | 0.90 | |
| Gestation (weeks) | 29 (27–31) | 29 (27–30) | 0.029 | |
| Males | 55.2 | 54.8 | 1.01 (0.90 to 1.14) | |
| Multiples | 22.4 | 29.4 | 0.69 (0.60 to 0.79) | |
| LSCS | 55.2 | 57.5 | 0.91 (0.81 to 1.03) | |
| Antenatal steroids | 84.5 | 88.2 | 0.72 (0.61 to 0.86) | |
| Transferred | 31.0 | 60.7 | 0.29 (0.25 to 0.33) | |
| Surfactant | 65.6 | 48.3 | 2.04 (1.81 to 2.29) | |
| Ventilated | 62.5 | 61.7 | 1.03 (0.92 to 1.17) | |
| CPAP | 53.1 | 73.9 | 0.40 (0.35 to 0.46) | |
| CRIB II | 6 (4–9) | 6 (3–10) | 0.72 | |
| Length of stay for surviving infants (days) | 43 (30–64) | 56 (42–78) | <0.0001 | |
| Oxygen on day 28 (% of infants alive on day 28) | 32.5 | 30.3 | 1.11 (0.97 to 1.26) | |
| Mortality to discharge | 13.6 | 12.4 | 1.12 (0.94 to 1.33) | |
Values are median (IQR) or percentage.
CPAP, continuous positive airway pressure; CRIB, clinical risk index for babies; LSCS, lower segment caesarean section; NSW/ACT, New South Wales/the Australian Capital Territory.