Table 4.

Treatment strategies.

Variable	Era I	Era II	Era III	p	p for trend
	1999–2000	2001–2006	2007–2013
	2,146 pts	2,572 pts	2,899 pts
Prenatal steroids (%)	12.1	14.4	22.6	<0.0001	<0.0001
Surfactant (%)	29.3	28.9	15.6	<0.0001	<0.0001
Inhaled nitric oxide (%)	27.1	50.5	61.6	<0.0001	<0.0001
ECMO (%)	37.5	31.6	30.3	<0.0001	<0.0001
Age at operation (days)	6.1 (0.2)	7.3 (0.2)	7.7 (0.2)	<0.0001	<0.0001
MAS (%)	0.1	2.1	15.3	<0.0001	<0.0001
Open thoracic approach (%)	4.2	4.0	5.3	0.1010	0.0909
Thoracoscopy (%)	0.0	69.9	90.2	<0.0001	<0.0001
Patch (%)	46.7	51.4	54.2	<0.0001	<0.0001
Chest tube (%)	65.0	42.8	34.9	<0.0001	<0.0001

Results are mean (SE) or prevalence, as appropriate.

ECMO, extracorporeal membrane oxygenation; MAS, minimal access surgery.

Sydak-adjusted p-value <0.0027 was considered significant.