Salas 2018.

Study characteristics
Methods	Randomised controlled trial
Participants	Preterm infants (< 29 weeks', appropriate weight for gestation) Neonatal Unit, Beth Israel Deaconess Medical Center, Boston, and University of Alabama at Birmingham Hospital, USA (2016 to 2017)
Interventions	Delayed progressive enteral feeding (> 96 hours after birth, 30 infants) versus earlier enteral feeding (< 48 hours, 30 infants), with feed volumes advanced by 24  mL/kg/d Infants received expressed maternal milk (first choice), pasteurised donor human milk (second choice), or artificial formula (third choice).
Outcomes	NEC (Bell stage 2/3) Mortality Invasive infection Duration of hospitalisation
Notes	Mean gestation at birth: 26 weeks' Mean birth weight: 833 g
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated sequence
Allocation concealment (selection bias)	Low risk	Opaque sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	High risk	Unmasked
Blinding of outcome assessment (detection bias) All outcomes	High risk	Unmasked
Incomplete outcome data (attrition bias) All outcomes	Low risk	Near‐complete cohort
Selective reporting (reporting bias)	Low risk	Unlikely
Other bias	Low risk	No evidence baseline imbalance