Sunshine 1987.

Methods	R, DB, 5 parallel groups. Single oral dose Medication administered when baseline pain reached a moderate to severe intensity Pain assessed at 0, 0.5, 1, 2, 3, 4 h
Participants	Episiotomy, Caesarian section or gynaecological operations N = 195 All F Mean age 26 years
Interventions	Ibuprofen + codeine 200/30 mg, n = 40 Ibuprofen + codeine 400/60 mg, n = 40 Ibuprofen 40 mg, n = 38 Codeine 60 mg, n = 37 Placebo, n = 40
Outcomes	PI: standard 4‐point scale PR: standard 5‐point scale Use of rescue medication Adverse events Withdrawals
Notes	Oxford Quality Score: R1, DB2, W1. Total = 4/5 Rescue medication allowed after 1 h
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"All unit doses were identical in appearance and packaging"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	"All unit doses were identical in appearance and packaging"
Size	High risk	< 50 participants per treatment arm

DB: double‐blind; F: female; M: male; N: number of participants in study; n: number of participants in treatment arm; PGE: patient global evaluation; PI: pain intensity; PR: pain relief; R: randomised; VAS: visual analogue scale; W: withdrawals