Risk of bias for analysis 2.1 Risk of necrotising enterocolitis stage ≥ 2.

Study

Bias

Randomisation process

Deviations from intended interventions

Missing outcome data

Measurement of the outcome

Selection of the reported results

Overall

Authors' judgement

Support for judgement

Authors' judgement

Support for judgement

Authors' judgement

Support for judgement

Authors' judgement

Support for judgement

Authors' judgement

Support for judgement

Authors' judgement

Support for judgement

Singh 2018

Low risk of bias

The randomization sequence was computer generated and permuted, even numbered, randomly varying block sizes were generated with a 1:1 allocation ratio. The allocation sequence was concealed using serially numbered opaque sealed envelopes.

Low risk of bias

Part 1: There were no deviations from the intended intervention (Low risk) Part 2: Modified intention to treat analysis was used (Low risk)

Low risk of bias

All 87 randomised infants were included in the analysis.

Low risk of bias

Though masking was not done, 'NEC' is an objective outcome and is less prone to detection bias.

Low risk of bias

Study protocol had been published. All proposed outcomes were reported.

Low risk of bias

'Low risk' in all domains.