London 1983a

Methods	RCT
Participants	Setting: Sinai Hospital of Baltimore, MD, USA (assumed from affiliation) Inclusion criteria: women with no systemic medical illness, experiencing moderate to severe episiotomy pain within 48 hours following an otherwise uncomplicated vaginal birth Exclusion criteria: "those used by Hermann et al"
Interventions	Aspirin (N randomised was unclear; N = 40 analysed) 650 mg aspirin; single dose in identical capsules Placebo (N randomised was unclear; N = 40 analysed) Placebo; single dose in identical capsules
Outcomes	Adequate pain relief as reported by the woman: one investigator assessed pain intensity and relief hourly for 6 hours; Though SPID and TOTPAR scores were reported, the scales used to measure pain intensity and relief were not reported, and thus these data could not be used to calculate 'Adequate pain relief as reported by the woman' Women's "overall impression" was reported (excellent, very good, good, fair and poor); excellent, very good and good ratings were used to calculate 'Adequate pain relief as reported by the woman' (taken at 6 hours) Need for additional pain relief in the first 48 hours for perineal pain: frequency of re‐medication Maternal adverse effects: women were observed hourly for adverse reactions
Notes	Funding: "We would like to acknowledge the support of Sandoz, Inc. in this study" Declarations of interests: not reported Additional arms: this was a 4‐arm trial also assessed fluproquazone 100 mg (N = 41 analysed) and 200 mg (N = 39 analysed); we included only the relevant arms in this review
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomly assigned"
Allocation concealment (selection bias)	Unclear risk	No detail provided
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quotes: "double‐blind"… "All medication was supplied in identical capsules… packaged in individually sealed envelopes"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Considered reasonable to assume blinding
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	In the whole trial, there were 166 who entered, and 160 provided "valid data for analyses"; other losses/exclusions not clearly reported
Selective reporting (reporting bias)	Unclear risk	No access to trial protocol to further assess; scales used to assess pain intensity and relief (needed to use SPID and TOTPAR scores to calculate adequate pain relief) were not reported
Other bias	Unclear risk	Baseline characteristics not reported