Pourarian 2008.

Methods	One centre, randomised controlled trial, conducted in Shiraz, Republic of Iran. Study period: a 6‐month period in 2001
Participants	20 preterm infants with ECHO‐confirmed PDA Ibuprofen: 10 infants, mean (SD) PMA 31.3 (4.4) weeks; BW 1860 (402) grams Indomethacin: 10 infants, mean (SD) PMA 33.2 (3.1) weeks; BW 1720 (630) grams
Interventions	Ibuprofen: oral suspension containing 100 mg/5 mL was given as an initial dose of 10 mg/kg, followed by 2 further doses of 5 mg/kg at 24‐hour intervals Indomethacin: powder content of an indomethacin 25 mg capsule was freshly prepared by dissolving in 25 mL distilled water. This was given orally as 0.2 mg/kg for 3 doses at 24‐hour intervals Administration of the second or third doses of each drug was dependent on achievement of ductal closure after the initial doses
Outcomes	Primary outcome: ductal closure Secondary outcomes: need for surgical closure, NEC, change in mean serum creatinine levels before and after treatment, increase in BUN level > 14 µmol/L, and thrombocytopenia < 50,000 mm3
Notes	No information on funding provided
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information provided
Allocation concealment (selection bias)	High risk	"As soon as the diagnosis (of PDA) was made for the 1st eligible baby, he/she was enrolled to the ibuprofen group and then the next eligible baby was assigned to the indomethacin group, and so on". This statement clearly indicated that the infants were not allocated to the two groups in a concealed manner
Blinding of participants and personnel (performance bias) All outcomes	High risk	The researchers were aware of group assignment ‐ see allocation concealment
Blinding of outcome assessment (detection bias) All outcomes	High risk	The researchers were aware of group assignment ‐ see allocation concealment
Incomplete outcome data (attrition bias) All outcomes	Low risk	Results for all randomised infants were reported
Selective reporting (reporting bias)	Unclear risk	Study protocol was not available to us so we could not ascertain if there were deviations from the protocol
Other bias	Low risk	Study appeared free of other bias