Liu 2011.

Methods	Single‐centre randomised trial.
Participants	84 infants allocated to 3 ventilation groups: VTV (n = 31), PLV (n = 30) and high‐frequency ventilation (n = 23). Only data from the 61 infants ventilated with PLV and VTV are included in meta‐analysis. Inclusion criteria: neonatal RDS, defined blood gas/oxygenation criteria, age < 12 h, consent to surfactant. Exclusion criteria: congenital respiratory/cardiac malformations, pulmonary haemorrhage/gas leak/congenital pneumonia/meconium aspiration/wet lung/congenital heart disease/IVH grade III‐IV.
Interventions	Ventilator: Draeger Babylog 8000 (VTV group) and VIP Bird (PLV group). VTV group (n = 31): SIPPV‐VG. Set expired VTtarget 4.0‐6.0 mL/kg, rate 30‐40/min. Pmax limit: not described. PLV group (n = 30): IMV, PIP 20‐25 cmH2O, rate 30‐40/min. Duration of intervention: not stated.
Outcomes	No clearly reported primary outcome. Included in meta‐analysis: duration PPV, air leak, IVH grade 3‐4 Excluded from meta‐analysis: mortality, data on oxygenation, ventilator‐associated pneumonia.
Supplemental data	Protocol and clarification on methods and results sought, but not received.
Notes	Denominators of outcomes beyond intervention periods were unclear due to challenges following up participants who had transferred to other hospitals or who were withdrawn from active clinical management for financial reasons. Only outcomes which occurred during intervention period were included in meta‐analysis.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Random number table used, method not specified. Unequal allocation to 3 groups (PLV, VTV and high‐frequency ventilation), and overall substantially more boys (n = 57) than girls (n = 27) included.
Allocation concealment (selection bias)	Unclear risk	No information provided.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No.
Intervention bias (strict vs hybrid studies)	High risk	Hybrid study: different ventilators.
Incomplete outcome data (attrition bias) All outcomes	High risk	Completeness of follow‐up not stated.
Selective reporting (reporting bias)	Unclear risk	No trial registration.
Other bias	Low risk