Lucas 1984a

Methods	Randomised controlled trial
Participants	159 infants of birth weight < 1850 g Stratified by birth weight < 1200 g and 1201 g to 1850 g Infants with congenital abnormalities excluded. Infants with intrauterine growth restriction not excluded Study undertaken in the early 1980s in neonatal units in the Anglia region of the UK
Interventions	Preterm formula milk (N = 76) versus donor (mainly "drip") breast milk (N = 83) The formula was intended to be delivered at 180 mL/kg/day versus the breast milk at 200 mL/kg/day Feeds were assigned until the infant reached a weight of 2000 g or until discharge from the neonatal unit
Outcomes	Short‐term outcomes: Time to regain birth weight (62 infants). Rates of change in weight (58 infants), crown‐heel length (26 infants) and head circumference (48 infants) from the point of regained birth weight until discharge from the neonatal unit or reaching a weight of 2000 g Incidence of NEC ‐ suspected and confirmed reported on complete cohort of 159 infants Longer‐term outcomes: Validated neurological assessment at 18 months in 122 (85%) of surviving infants Bayley Mental Development Index and Psychomotor Development Index at 18 months post‐term, in 114 (94%) of surviving infants suitable for the assessment Growth performance in surviving infants (weight, length and head circumference) at 9 months (110 infants), 18 months (136 infants) and 7.5 to 8 years (130 infants) post‐term
Notes	The first "interim" report provided data on short‐term growth outcomes in a predefined subset of the total cohort recruited. Follow‐up at 18 months was achieved for more than 80% of surviving infants. Developmental assessments (Bayley Psychomotor and Mental Development Indices) at 18 months post‐term were reported for 114 of the 159 children originally enrolled in the study. 16 children had died and 7 had been lost to follow‐up. 12 surviving children had cerebral palsy affecting fine motor skills and these children were not assessed. A further 10 children were not assessed due to severe visual or hearing impairment or because follow‐up data were obtained by telephone for geographical reasons.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Balanced randomisation sequence was prepared for each centre, within strata defined by birth weight (method of sequence generation not stated explicitly)
Allocation concealment (selection bias)	Low risk	Sealed, numbered envelopes
Blinding (performance bias and detection bias) All outcomes	Unclear risk	No information given
Incomplete outcome data (attrition bias) All outcomes	Low risk	100% assessment of in‐hospital outcomes and > 80% follow‐up for long‐term outcomes (except for cognitive outcomes (verbal and performance intelligence quotient), which were assessed in about 20% of participants at ages 8 and 16 years)
Selective reporting (reporting bias)	Unclear risk	Protocol not available
Other bias	Unclear risk	Funded by Farley Health Products