Prakash 2019.

Study characteristics
Methods	RCT
Participants	113 preterm infants (28–34 weeks' gestation) with respiratory distress treated with bubble CPAP (pressure source not stated) within 6 hours after birth
Interventions	Mask (manufacturer not stated): n = 56 Prongs (manufacturer not stated): n = 57
Outcomes	Treatment failure (mechanical ventilation) Duration of CPAP use Duration of hospitalisation Nasal trauma Patent ductus arteriosus Retinopathy of prematurity Necrotising enterocolitis Death before discharge and chronic lung disease not reported
Notes	Setting: Uttar Pradesh, India (2016–2018) Funding: no specific funding Author contacted 28 August 2021; no reply received
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number table.
Allocation concealment (selection bias)	Unclear risk	Not stated.
Blinding (performance bias and detection bias) All outcomes	High risk	Open label.
Incomplete outcome data (attrition bias) All outcomes	High risk	33/113 randomised infants excluded because of nasal CPAP treatment failure.
Selective reporting (reporting bias)	Unclear risk	Mortality not reported.
Other bias	Low risk	No evidence imbalance in baseline demographics.