Smyth 1995.

Methods	Randomized Multicenter Blinding of randomization: Yes (opaque, sealed envelopes) Blinding of intervention: Yes (drug administration team) Complete Follow‐up: Short term: Yes Long term: 96% Blinding of outcome measurement: Yes Stratification: Based on birthweight and gender Long‐term follow up: Casiro 1995, Courtney 1995
Participants	Neonates Birthweight 500‐749 grams Respiratory distress syndrome Assisted ventilation a/A ratio <0.22 Age 2‐24 hours Infants randomized: Exosurf Neonatal = 115 Control = 109
Interventions	Intratracheal Exosurf Neonatal (5 ml/kg) or sham treatment (air) Second dose 12 hours later if infant remained on assisted ventilation
Outcomes	PRIMARY OUTCOME: Neonatal mortality bronchopulmonary dysplasia survival at 28 days without BPD SECONDARY OUTCOMES cardiorespiratory support complications of prematurity
Notes	Primary outcome (neonatal mortality, BPD, survival without BPD) reported based on intention to treat. Other complications of prematurity reported based on treatment received.