De Vroey 1978.

Study characteristics
Methods	Multi‐arm RCT ‐ 5 groups
Participants	Primiparous women aged between 16 ‐ 40 years who had a medio‐lateral episiotomy during the course of an otherwise uncomplicated delivery; delivery within previous 48 hours and complained of moderate to severe pain Department of Obstetrics and Gynaecology of the St. Christiana Clinic, Belgium
Interventions	Intervention: diflunisal 125 mg (N = 30); diflunisal 250 mg (N = 30); diflunisal 500 mg (N = 30) and aspirin 600 mg (N = 32) Comparison: placebo (N = 31)
Outcomes	Pain/pain relief (presented as mean pain scores on a 4‐point rating scale; 0 = none, 1 = mild, 2 = moderate and 3 = severe) Maternal drug adverse effects Pain severity was assessed before drug administration and then at hourly intervals up to 6 ‐ 8 hours; 4‐ and 6‐hour data available and extracted separately
Notes	Dates of study: NR Funding sources: NR Declarations of interest: NR
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No clear statement on method used.
Allocation concealment (selection bias)	Unclear risk	No clear statement
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No clear statement
Incomplete outcome data (attrition bias) All outcomes	Low risk	Clear information, including reasons, were provided on 5 exclusions after randomisation and on 3 withdrawals (9%) of the 32 women in the aspirin 600 mg group after treatment. (The attrition rate was 0% for all other groups)
Selective reporting (reporting bias)	Low risk	All prespecified outcomes were reported
Other bias	Low risk	None obvious; all women were primiparas with equal distribution across groups, based on initial severity of pain