Arif 2005

Methods	Randomised open controlled study Study location: single‐centre study performed in Istanbul, Turkey Study period: 1993 to 2002
Participants	292 preterm infants < 33 weeks' GA, birth weight < 1500 grams, no blood sampling > 10 mL in the first 7 days after birth, no previous blood transfusion, no IVH > grade 1, no history of hematological disease, no urinary tract infection or sepsis
Interventions	142 infants in EPO group received EPO (EPREX 2000, Santa‐Farma‐Gurel, Istanbul) 200 IU/kg SC from the seventh day of life and continued twice weekly (400 IU/kg/week, low dose) for 6 weeks. 150 infants in the control group did not receive a placebo. Both groups received iron (3 to 5 mg/kg/d orally) (high dose).
Outcomes	Use of 1 or more red blood cell transfusions Mortality NEC ROP (stage not reported) BP
Notes	Infants who had received red blood cell transfusion before study entry were excluded. Transfusion guidelines were in place. The iron dose varied from 3 to 5 mg/kg/d, but we included this as a high dose in our subgroup analyses.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐assisted randomisation scheme
Allocation concealment (selection bias)	Unclear risk	No information provided
Blinding of participants and personnel (performance bias) All outcomes	High risk	No placebo used
Blinding of outcome assessment (detection bias) All outcomes	High risk	No placebo used
Incomplete outcome data (attrition bias) All outcomes	Low risk	Complete follow‐up: yes
Selective reporting (reporting bias)	Unclear risk	The protocol for the study was not available to us; therefore we cannot ascertain whether deviations from the protocol occurred.
Other bias	Low risk	Appears free of other bias