Corbet 1991.

Methods	Randomized Multicenter study Blinding of randomization: yes (sealed envelopes) Blinding of intervention: yes (staff not involved in clinical care administered assigned treatment in screened area Complete follow‐up: yes Blinding of outcome measures: yes Stratification based on gestational age and gender Long‐term follow‐up: Corbet (1995), Sell (1995): 82% of survivors evaluated
Participants	Premature infants Birthweight 700 to 1100 grams No proven lung maturity No major congenital malformation No fetal growth retardation No evidence of hydrops fetalis No purulent amnionitis No maternal heroin addition Infants randomized: Exosurf = 224 Air Placebo = 222
Interventions	Intratracheal Exosurf Neonatal (5ml/kg) or sham treatment (air) in delivery room within 30 minutes after birth
Outcomes	PRIMARY OUTCOME: Survival at age 28 days without bronchopulmonary dysplasia SECONDARY OUTCOMES: Respiratory distress, mortality, complications of prematurity FOLLOW‐UP: Assessed at 1 year adjusted age
Notes	Evaluation of BPD, neonatal mortality does not include infants with congenital malformation or congenital pneumonia
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Stratification based on gestational age and gender
Allocation concealment?	Low risk	Blinding of randomization: yes (sealed envelopes)
Blinding? All outcomes	Low risk	Blinding of intervention: yes (staff not involved in clinical care administered assigned treatment in screened area Blinding of outcome measures: yes
Incomplete outcome data addressed? All outcomes	Low risk	Complete follow‐up: yes Long‐term follow‐up: Corbet (1995), Sell (1995): 82% of survivors evaluated
Free of selective reporting?	Low risk
Free of other bias?	Low risk