Fox 1990.

Methods	Cross‐over RCT of prone and supine positions
Participants	Included: 25 preterm infants with a gestational age of 36 weeks or less, who were receiving intermittent mandatory ventilation and/or CPAP and supplemental oxygen for respiratory distress syndrome, and had an umbilical artery oxygen tension catheter in situ Excluded: infants receiving paralysing drugs Mean gestational age: 31 weeks; mean age: 58 hours; mean weight: 1633 g Setting: level III NICU, US
Interventions	All in incubators, on water mattress with head elevated 30 degrees, infants were allowed to settle to sleep after positioning before data collection commenced Ventilatory parameters and FiO2 remained unchanged
Outcomes	PaO2 Sampling occurred every 30 seconds for 15 minutes in each position; all data collected within a 1‐hour period
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	First position randomly assigned by coin toss
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not stated
Incomplete outcome data (attrition bias) All outcomes	Low risk	Appears to be no loss to follow‐up