Preterm infants in 19 US centres (n= 1,824).
Red-cell transfusions at higher haemoglobin threshold (n= 911).
Red-cell transfusions at lower haemoglobin threshold (n= 913).
Primary outcome data were available for 1,692 infants (92.8%). Of 845 infants in the higher-threshold group, 423 (50.1%) died or survived with neurodevelopmental impairment, as compared with 422 of 847 infants (49.8%) in the lower-threshold group. At 2 years, the higher- and lower-threshold groups had similar incidences of death 16.2% and 15.0%, respectively and neurodevelopmental impairment 39.6% and 40.3%, respectively. At discharge from the hospital, the incidences of survival without severe complications were 28.5% and 30.9%, respectively. Serious adverse events occurred in 22.7% and 21.7%, respectively.