Schmölzer 2018.

Methods	Prospective randomised parallel controlled trial Pilot (5 infants randomised to each group) Setting: Royal Alexandra Hospital, Edmonton, Alberta, Canada
Participants	Inclusion criteria: inborn infants between 23+0 and 32+6 weeks of postmenstrual age who required chest compressions in the delivery room Exclusion criteria: congenital abnormality or condition that might have an adverse effect on breathing or ventilation (e.g. congenital pulmonary or airway anomalies, congenital diaphragmatic hernia, congenital heart disease requiring intervention in neonatal period)
Interventions	SLI group: SLI of 20 + 20 seconds, plus uninterrupted chest compression at a rate of 90/min Control group: 3:1 compression:ventilation (C:V) ratio according to current resuscitation guidelines Default settings for airway pressures: PIP of 24 cmH₂O and PEEP of 6 cmH₂O
Outcomes	Primary outcome: return of spontaneous circulation Secondary outcomes (we obtained the following information directly from trial authors): all mortality before discharge from hospital, delivery room interventions (rate of intubation, use of epinephrine), mechanical ventilation, use of inotropic agents, NEC, moderate to severe BPD, ROP, brain injury as indicated by abnormal neuroimaging
Notes	Trial was registered at ClinicalTrials.gov: NCT02083705
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Low risk	A sequentially numbered, brown, sealed envelope contained a folded card box with treatment allocation
Blinding (performance bias and detection bias) All outcomes	High risk	Assigned intervention could not be blinded to the resuscitation team
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Both data collector and outcome assessor were unaware of group allocation
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not reported
Selective reporting (reporting bias)	High risk	Trial was registered at ClinicalTrials.gov: NCT02083705. However, secondary outcomes were not specified
Other bias	Low risk	Appears free of other bias