Jannatdoust 2014.

Study characteristics
Methods	Single‐centre randomized controlled trial
Participants	Inclusion criteria GA less than 32 weeks and birth weight 800 g to 1500 g Exclusion criteria Congenital abnormalities severe asphyxia (5‐minute Apgar score < 7 or initial pH < 7.1) Moderate thrombocytopenia (50,000/μL) High serum creatinine (1.8 mg/dL) Obvious bleeding (respiratory, skin, digestive, urinary, mucous) Antenatal receipt of indomethacin
Interventions	Active intervention (n = 35) IV indomethacin; initial dose 0.2 mg/kg administered between 2 to 12 hours followed by 2 doses of 0.1 mg/kg each at 24 and 48 hours Control (n = 35) No placebo
Outcomes	Relevant outcomes for this study included Mortality IVH Treatment for symptomatic PDA
Notes	Primary study location: Alzahra Educational‐Medical Center, Tabriz, Iran Study period: June 2010 to December 2012 Trial registration: IRCT201107117010N1
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	computerized randomized number generator used
Allocation concealment (selection bias)	Low risk	Random allocation determined by Rand List Software
Blinding of participants and personnel (performance bias) All outcomes	High risk	No mention of placebo use in control group and no mention of blinding efforts.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No mention of placebo use in control group and no mention of blinding efforts.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All outcomes reported for all randomized infants.
Selective reporting (reporting bias)	Unclear risk	Trial was registered retrospectively with the Iranian Registry of Clinical Trials (IRCT201107117010N1).
Other bias	Unclear risk	Given this was an unblinded study and it was retrospectively registered, difficult to assess if there were other sources of bias.