PDA, patent ductus arteriosus, GA gestational age, RSS respiratory severity score, ANS antenatal steroids, PMA post menstrual age, NCPAP nasal continuous positive airway pressure, NIPPV nasal intermittent positive pressure ventilation, VI ventilation index, Fio2 fraction of inspired oxygen.

^a Data are given as median (interquartile range) or n/N (%)

^b Others include high-flow nasal cannula, nasal cannula, and room air