Stevenson 1992.

Methods	Randomized Multicenter Blinding of randomization: Yes (sealed envelopes) Blinding of intervention: Attempted (treatment administered by a separate dosing team in a screened area) Complete follow‐up: yes Blinding of outcome measurement: yes Stratification by Birthweight: (500 to 599 g, 600 to 699 g) and gender Long‐term follow‐up: Corbet (1995), Walther (1995): 83% of survivors evaluated
Participants	Premature infants Inborn Birthweight 500‐699 grams No proven lung maturity No major congenital malformation No fetal growth retardation No evidence of hydrops fetalis No purulent amnionitis No maternal heroin addiction Infants randomized: Exosurf = 109 Air Placebo = 106
Interventions	Intratracheal Exosurf Neonatal (5ml/kg) or sham treatment (air) in delivery room shortly after birth
Outcomes	PRIMARY OUTCOME: Neonatal mortality SECONDARY OUTCOMES: Ventilatory requirements Death due to RDS Bronchopulmonary dysplasia Complications of prematurity FOLLOW‐UP: Assessed at 1 year adjusted age
Notes	Primary analysis reported as intention to treat (BPD, mortality), other outcomes reported based on treatment administered
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Stratification by Birthweight: (500 to 599 g, 600 to 699 g) and gender
Allocation concealment?	Low risk	Blinding of randomization: Yes (sealed envelopes)
Blinding? All outcomes	Low risk	Blinding of intervention: Attempted (treatment administered by a separate dosing team in a screened area) Blinding of outcome measurement: yes
Incomplete outcome data addressed? All outcomes	Low risk	Complete follow‐up: yes Long‐term follow‐up: Corbet (1995), Walther (1995): 83% of survivors evaluated
Free of selective reporting?	Low risk
Free of other bias?	Low risk