Study	Reason for exclusion
Bard 1996	Infants were not randomly assigned to target two different arterial blood oxygen saturations (90% and 95%). Infants acted as their own controls. This was not a random or quasi‐random trial and was thus excluded from the review.
Cunningham 1995	This non‐randomized, retrospective study assessed the effects of variability of oxygen levels, as measured by transcutaneous oxygen monitoring, on the incidence of retinopathy of prematurity. Patient allocation was not randomized, and thus the study was excluded from the review.
Deulofeut 2007	This was a non‐randomized study of infants from January 2000 to December 2004, where there was a change from SpO2 92‐100% to SpO2 85‐93% from January 2003. Since allocation of treatment was non‐randomized, this study was excluded from the review.
Engleson 1958	This non‐randomized trial addressed a different question from that under review. It examined the effects of keeping preterm infants at oxygen concentrations below that of room air, and was thus not included in the review.
Fitzgerald 1998	Infants in this study were randomized to receive either air/usual supplementary oxygen (to maintain SpO2 >93%) or increased supplementary oxygen (to maintain SpO2 >97%) only for one night whilst the sleep study was done. Included trials randomized infants to an ongoing policy of higher / lower SpO2. Infants also already had CLD at the start of the study (which was one of this study's population inclusion criteria).
Gaynon 1997	The study was a retrospective analysis of different target ranges of oxygen saturation on the incidence of ROP. There was no random allocation of patients to different treatment groups, thus the trial was excluded from the review.
Kitchen 1978	This study was a randomized trial of a "package" of intensive care, including intravenous glucose, umbilical arterial catheterisation, bicarbonate infusion, and high PaO2 levels, vs. the standard neonatal care regimen of the late 1960s. The trial was excluded from the review because the entire "package" of interventions, rather than the separate elements within it, was the randomized intervention. Thus, other interventions that could affect clinical outcomes were unbalanced between oxygen exposure groups.
Lundstrom 1995	This randomized trial addressed a different question from that under review. It compared the use of atmospheric air vs. 80% oxygen for preterm infants during initial stabilization in the delivery room, and was thus excluded from the review.
Mendicini 1971	This study was a randomized trial of a "package" of intensive care, including intravenous glucose, bicarbonate infusion, and high PaO2 levels, vs. the standard neonatal care regimen of the late 1960s. The trial was excluded from the review because the entire "package" of interventions, rather than the separate elements within it, was the randomized intervention. Thus, other interventions that could affect clinical outcomes were unbalanced between oxygen exposure groups.
Schulze 1995	This was a non‐randomized, crossover trial comparing the effects of two different oxygen saturation target ranges on cardiac output, oxygen extraction, and oxygen consumption in mechanically ventilated, low birth weight infants. As treatment allocation was not random or quasi‐random, the trial was excluded from the review.
STOP‐ROP 2000	This trial included preterm/LBW infants with pre‐threshold ROP. The intervention tested was supplemental oxygen for the treatment of pre‐threshold ROP, not a preventative strategy. The results of this trial will be included in a separate Cochrane review entitled: "Supplemental oxygen in the treatment of pre‐threshold retinopathy of prematurity" (Lloyd J, Askie LM, Smith J, Tarnow‐Mordi WO).
Wallace 2007	This was a non‐randomized retrospective cohort study of infants. Eligible infants born between October 1, 2002, and July 31, 2003, were given SpO2 98‐100%. Eligible infants born between January 1, 2004, and April 30, 2005, were given SpO2 90‐96%. Since allocation of treatment was non‐randomized, this study was excluded from the review.
Weintraub 1956	The planned scheme of quasi‐random, alternate allocation was not adhered to, resulting in the possibility of substantial selection bias, and the study was thus excluded from the review.
Wright 2006	This was a non‐randomized prospective observational study of infants from 3 centres where there was a change in SpO2 from >90%, 89‐94% or 90‐95% to 83‐93% for all centres. Eligible infants born after the transition year were given the lower SpO2 treatment. Since allocation of treatment was non‐randomized, this study was excluded from the review.