Table 3

Primary and main secondary outcomes in ETTNO and TOP trials

Transfusion threshold groupETTNO trial24 TOP trial25
No of subjects randomised492521911913
Mean gestational age, weeks26262626
Approximate haemoglobin separation between higher and lower groups*1.0 g/dL2.0 g/dL
Infants with delayed cord clamping or cord milking, %63612724
No of subjects with primary outcome, neurodevelopmental impairment or death450478845847
Overall follow-up rate per study including both Higher and Lower groups, %91.692.8
 Primary outcome, %
 – OR24 or adjusted relative risk25 (95% CI)
1.05 (0.80 to 1.39)1.00 (0.92 to 1.10)
 Death, %
 – OR24 or adjusted relative risk25 (95% CI)
0.91 (0.58 to 1.45)1.07 (0.87 to 1.32)
 Neurodevelomental impairment, %
 – OR24 or adjusted relative risk25 (95% CI)
1.12 (0.83 to 1.51)1.00 (0.88 to 1.13)
Mean no of transfusions2.61.7†6.24.4‡
Infants never transfused, %2140‡312‡
Necrotising enterocolitis§, %
Patent ductus arteriosus§, %41.537.844.547.8
Retinopathy of prematurity§, grade ≥3, %15.913.019.717.2
Severe intraventricular haemorrhage or periventricular leucomalacia§¶No significant differenceNo significant difference
Bronchopulmonary dysplasia**28.426.059.056.3
  • *Estimated from figure 2 for the ETTNO trial and from figure 2A for the TOP trial.

  • †Unable to compute p value for means, although the medians reported in eTable 224 were 2 and 1, and the IQRs overlapped.

  • ‡Significantly different (p<0.05), higher vs lower transfusion threshold group.

  • §The differences between higher and lower groups were not significant for either trial.

  • ¶The values are not comparable between studies because severe intraventricular haemorrhage and periventricular leucomalacia were combined in TOP but not in ETTNO.

  • **Bronchopulmonary dysplasia defined as oxygen use at 36 weeks’ postmenstrual age.