Sankaran 1996.

Study characteristics
Methods	Parallel randomised controlled trial, multi‐centre
Participants	Inclusion criteria healthy preterm infants with birth weight 600–1600 g, gestational age 24–34 weeks. Mother was able to supply ≥ 90% of her baby's milk supply daily after the addition of fortifier. The infant had received and tolerated ≥ 120 mL/kg/day of full strength preterm milk for 3 consecutive days Exclusion criteria receiving total parenteral nutrition had major congenital anomalies experienced renal dysfunction needed special formulas other than Similac Special Care Setting: 2 neonatal intensive care units in Canada Study date: not reported
Interventions	Intervention: bovine based liquid human milk fortifier containing 1.09 g protein added to 100 mL EBM (n = 29) Control: bovine based human milk fortifier containing 0.7 g protein added to 100 mL EBM (n = 31) Calorie content: non‐isocaloric, 73.5 kcal (intervention) vs 80.6 kcal (control) energy per 100 mL fortified EBM (9% difference) Start of intervention: tolerating full feeds of 120 mL/kg/day preterm milk after 3 consecutive days Mean age at trial entry: 20.1 days (SE 2.4) in intervention group and 24.5 days (SE 3.1) in control group End of intervention: when the infants reached 2 kg bodyweight or gained 35 g/day averaged over 10 days
Outcomes	Outcomes were not specified as primary or secondary weight gain length gain head circumference gain serum albumin protein phosphorus calcium alkaline phosphatase
Notes	Conflict of interest: none declared Source of funding: Abbott Laboratories and Mead Johnson Canada partially funded the study. Note regarding the protein concentration: there was insufficient information regarding the protein concentration of the 2 human milk fortifier as g/100 mL EBM and following calculations were done to determine the protein concentration. Note: although confirmation was sought from the authors, no response has been received to date. Intervention (liquid, mixed with EBM in 1:1 ratio): liquid human milk fortifier containing 2.7 g protein per 124 mL as provided in the text, equal to 1.09 g/50 mL when mixed with 50 mL EBM, therefore the protein derived from the fortifier was 1.09 g/(50 + 50 mL). The final fortified EBM containing 2.6 g protein per 136 mL, half of the volume was derived from the liquid human milk fortifier which contained 1.48 g protein, therefore the protein concentration of EBM was 1.12 g/68 mL = 1.65 g/100 mL Control (powder, mixed with EBM as 4 packs/100 mL EBM): the final fortified EBM containing 2.9 g protein per 124 mL as provided in the text, and the protein from EBM was 2.05 g (based on 1.65 g/100 mL and 124 mL), therefore the protein derived from the fortifier was 0.85 g/124 mL = 0.7 g/100 mL. Note that the human milk fortifier used in the intervention group was liquid, therefore the added protein concentration was converted to gram per 100 mL of fortified EBM in this review.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer generated block randomisation.
Allocation concealment (selection bias)	Unclear risk	Insufficient information.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Trial was designed to determine the efficacy of the product, no intention to treat data reported. Attrition were described (41/60 infants' data were used for analysis) but unclear which group the infants originally enrolled in.
Selective reporting (reporting bias)	Unclear risk	Insufficient information.
Other bias	Unclear risk	Trial was sponsored by manufacturer, the role of whom was not described further.

EBM: expressed breast milk; GI: gastrointestinal; IQR: interquartile range; n: number of participants; SD: standard deviation; SE: standard error.