Table 5.
Predictive multivariable models for inpatient deaths and four major neonatal morbidities in survivors born at 22-25 weeks’ gestation in 1995 and 2006. Figures are odds ratios (95% confidence intervals)
| Death before discharge for all admissions (n=666 in 1995 and 1115 in 2006)* | Survivors (n=266 in 1995 and 593 in 2006) | ||||
|---|---|---|---|---|---|
| Severe abnormality† on cerebral scan‡ | Bronchopulmonary dysplasia (supplementary oxygen at 36 weeks PMA) | Supplementary oxygen at 40 weeks PMA | Laser treatment for retinopathy§ | ||
| Total No included | 1630 | 847 | 830 | 821 | 851 |
| 2006 v 1995 | 1.10 (0.85 to 1.43) | 1.17 (0.74 to 1.85) | 1.04 (0.72 to 1.50) | 1.12 (0.81 to 1.56) | 2.90 (1.71 to 4.92) |
| Significant clinical associates in combined cohorts: | |||||
| Gestational age (per week) | 0.73 (0.62 to 0.86) | — | 0.62 (0.45 to 0.85) | 0.61 (−0.47 to 0.80) | 0.50 (0.37 to 0.67) |
| Birth weight (per SD) | — | 0.69 (0.52 to 0.91) | 0.73 (0.57 to 0.92) | 0.71 (0.53 to 0.06) | |
| Male | 1.60 (1.27 to 2.01) | — | 2.08 (1.48 to 2.91) | 1.76 (1.31 to 2.36) | — |
| Chorioamnionitis | 0.61 (0.46 to 0.82) | — | — | — | — |
| Antenatal steroid¶ | 0.68 (0.53 to 0.86) | 0.55 (0.37 to 0.82) | — | — | — |
| Tocolysis | — | — | — | 1.51 (1.12 to 2.04) | — |
| Afro-Caribbean ethnicity | — | 0.48 (0.27 to 0.86) | — | — | 0.26 (0.15 to 0.46) |
| Vaginal delivery | 0.58 (0.43 to 0.78) | — | — | — | — |
| Heart rate >100 at 5 min | 0.56 (0.37 to 0.84) | — | — | — | — |
| Admission temperature ≥35°C | 0.75 (0.56 to 1.00) | — | 0.57 (0.33 to 0.98) | 0.64 (0.42 to 0.98) | — |
| CRIB 1 score** (per point): | |||||
| Combined cohort | — | — | 1.08 (1.00 to 1.15) | 1.07 (1.01 to 1.13) | — |
| 1995 cohort only | 1.32 (1.24 to 1.40) | — | — | — | — |
| 2006 cohort only | 1.22 (1.17 to 1.27) | — | — | — | 1.10 (1.02 to 1.18) |
PMA=postmenstrual age.
*Odds ratios additionally adjusted for antepartum haemorrhage in 2006 cohort (OR 0.62, 95%CI 0.43 to 0.88). Interaction of CRIB I with cohort is significant hence values for separate cohorts are given.
†Defined as last available cerebral ultrasound scan with any of ventriculomegaly, parenchymal cysts, haemorrhagic parenchymal infarct.
‡Odds ratios additionally adjusted for transfer within 24 hours of birth in 1995 cohort only(OR 3.08, 95%CI 1.36 to 6.96).
§Odds ratios additionally adjusted for antepartum haemorrhage in 1995 cohort only (OR 2.74, 95%CI 1.28 to 5.88).
¶Antenatal steroid given to mother >24 hours before birth.
**Clinical risk index for babies (CRIB I),19 centred on mean score (9.5) of combined admitted cohorts and to zero in both individual year cohorts.