COT (Canada).

Trial name or title	Canadian oxygen trial
Methods	Infants are randomized centrally by telephone. Randomization is stratified by gestational age (23‐25 and 26‐27 weeks) and by study centre. Alocation will incorporate variable block sizes. The concealed study allocation will be determined, in advance, using a computer‐based random number generator. The intervention monitored through Masimo Radical SET pulse oximeters are masked by offsetting the assigned SpO2 by +/‐3% points. Staff will (a) target SpO2 88‐92% and (b) aim to maximize time spent with SpO2 between 85‐95%. From 85‐95%, the offset will be 3% above or below the actual SpO2. Outside 85‐95%, study oximeters read actual SpO2. A sample size of 1200 infants has 80% power (2p=0.05) to detect an absolute 8% increase or decrease in the composite outcome of death or major disability at 2 years. This would mean one less infant who died or was disabled for every 12 infants managed in the optimal range. This would have similar power to detect a reduction in severe ROP from 10% to 7.8% and in CLD from 40% to 32%.
Participants	Infants <27 weeks' gestation at birth and <24 hours old
Interventions	Lower (Fn SpO2 85‐89%) vs higher (Fn SpO2 91‐95%) O2 targeting
Outcomes	Death or major disability (cognition, neuromotor function, vision, hearing) at 2 years corrected age, other secondary outcomes
Starting date	October 2006
Contact information	Dr Barbara Schmidt; Email: schmidt@mcmaster.ca
Notes