NPPB and bronchopulmonary dysplasia: The AUCs of the two ROC curves were 0.846 (0.809, 0.882) and 0.906 (0.877, 0.934) (P < 0.001), which showed that the level of NT-proBNP on the 7th day after birth (±2 days) greatly improved the predictive ability of moderate-to-severe BPD/death (Figure 3).