Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "using sequential numbers generated at the computer center of…"
Allocation concealment (selection bias)	Low risk	Quote: "The allocations were contained in opaque, sequentially numbered sealed envelopes"
Blinding of participants and personnel (performance bias)	Low risk	Quote: "Thus, the only personnel who knew of the infants’ group assignments were the investigators and those in the breast‐milk team who were not involved in the care of the study infants"
Blinding of outcome assessment (detection bias)	Low risk	Quote: "Whenever an infant was suspected to have NEC, the infant was evaluated by two senior‐attending neonatologists who did not know the group assignment of the infant"
Incomplete outcome data (attrition bias)	Low risk	Minimal loss to follow up
Selective reporting (reporting bias)	Low risk	Authors seem to report all the outcomes irrespective of their statistical significance
Other bias	Low risk	No other risk of bias was noted