O'Connor 2016.

Methods	Randomised controlled trial
Participants	363 VLBW infants whose mothers intended to breastfeed but whose own milk became insufficient from birth until 90 days of age or hospital discharge Four neonatal units in Ontario, Canada, 2010 to 2012
Interventions	Preterm formula (N = 182) versus donor breast milk (N = 181) given as a supplement to maternal breast milk (bovine‐based multinutrient‐fortified)
Outcomes	Cognitive composite score on the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley‐III) at 18 months post‐term Bayley‐III language and motor composite scores, mortality and morbidity index (late‐onset infection, NEC (Bell stage ≥ II), chronic lung disease, or retinopathy of prematurity (treated medically or surgically), and growth during the feeding intervention
Notes	"A similar percentage of infants in the donor milk group (28.2%) and formula group (26.9%) were exclusively fed mother’s milk". "Infants in both groups were fed substantial amounts of maternal milk, with approximately 25% in each group receiving only maternal milk, and the remainder receiving about 60% maternal milk".
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Computer‐driven third‐party randomisation service"
Allocation concealment (selection bias)	Low risk	Computer‐randomised
Blinding (performance bias and detection bias) All outcomes	Low risk	Families and clinicians "blinded"
Incomplete outcome data (attrition bias) All outcomes	Low risk	> 90% assessment for primary outcome
Selective reporting (reporting bias)	Low risk	No protocol deviations
Other bias	Unclear risk	Funded by the Canadian Institutes of Health Research (MOP No. 102638) and the Ontario Ministry of Health and Long‐Term Care (grant No. 06465)