Main Outcomes and Measures
BPD, death, NDI
Infants’ baseline risk of grades 2 to 3 BPD or death was estimated using the NICHD Neonatal BPD Outcome Estimator. Differences in absolute and relative treatment effects by baseline risk were evaluated using interaction terms in models fitted to the efficacy outcome of grades 2 to 3 BPD or death and the safety outcome of moderate or severe NDI or death by follow-up.