Chotigeat 2003.

Methods	Single centre, randomised, controlled trial conducted in Bangkok, Thailand. Study period: 1 January 2001 to 31 May 2002
Participants	30 preterm infants (GA ≤ 35 weeks, postnatal age ≤ 10 days) with an ECHO‐confirmed PDA Ibuprofen: 15 infants, mean (SD) GA 30.8 (2.3) weeks; BW 1412 (354) grams Indomethacin: 15 infants, mean (SD) GA 29.9 (2.9) weeks; BW 1434 (421) grams
Interventions	Ibuprofen: orally as a 3‐day treatment course every 24 hours Indomethacin: IV at 12‐hour intervals The doses of ibuprofen and indomethacin were not stated
Outcomes	PDA closure, need for surgical ligation, NEC
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)	Unclear risk	The infants were assigned to treatment group by random number
Blinding of participants and personnel (performance bias) All outcomes	High risk	Ibuprofen was given orally and indomethacin was given IV
Blinding of outcome assessment (detection bias) All outcomes	High risk	Ibuprofen was given orally and indomethacin was given IV. It is not stated that ECHOs were conducted by physicians blinded to the treatment the infant received
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcomes reported on all randomised infants
Selective reporting (reporting bias)	Unclear risk	Study protocol was not available to us and we could not ascertain whether there were deviations from the protocol
Other bias	Low risk	Appeared free of other bias