Procedures	Total Infants with HRF/PPHN (n=918)	Infants with HRF/PPHN
		Preterm infants (n=504)	T/NT infants (n=414)	P-value
Ventilation use, n (%)
Overall	865 (94.2)	474 (94.1)	391 (94.4)	0.7976
Time on ventilation (days), mean (SD)	3.6 (7.7)	4.7 (10.0)	2.2 (2.5)	<0.0001
Non-invasive ventilation	334 (36.4)	188 (37.3)	146 (35.3)	0.5235
Invasive mechanical ventilation	836 (91.1)	461 (91.5)	375 (90.6)	0.6386
ECMO, n (%)	46 (5.0)	10 (2.0)	36 (8.7)	<0.0001
Treatments, n (%)
Antibiotics	880 (95.9)	485 (96.2)	395 (95.4)	0.5351
Surfactants	544 (59.3)	359 (71.2)	185 (44.7)	<0.0001
Sildenafil	82 (8.9)	48 (9.5)	34 (8.2)	0.4882
Inhaled nitric oxide	863 (94.0)	473 (93.8)	390 (94.2)	0.8222
Time on inhaled nitric oxide (days), mean (SD)	7.2 (11.2)	8.2 (12.5)	5.9 (9.1)	0.0017
Mortality rate, n (%)	240 (26.1)	152 (30.2)	88 (21.3)	0.0023