Friedrich 1983

Methods	RCT
Participants	Setting: Department of Obstetrics and Gynaecology, Washington University, St Louis, Missouri, USA (assumed from affiliation) Inclusion criteria: women, suffering moderate or severe pain following episiotomy Exclusion criteria: current or recent history of gastrointestinal bleeding; peptic ulcer; other GI disorders; alcohol or drug abuse; disorders of the nervous system, kidney, heart or blood; known allergies to aspirin or aspirin‐like analgesics; conditions likely to interfere with absorption, distribution, metabolism, or excretion of drugs; other pain requiring narcotic analgesics; acute dermatitis or other skin lesions; past or present malignancies; taking corticosteroids or other NSAIDs, anticoagulants or other drugs that may interfere with study medication; experiencing pain due to other causes; breastfeeding
Interventions	Aspirin (N = 39 randomised) 650 mg aspirin Placebo (N = 40 randomised) All women: women received the study medication at the onset or recurrence of moderate or severe pain at least 16 but not more than 48 hours following induction of anaesthesia
Outcomes	Adequate pain relief as reported by the woman: pain intensity and relief at 0.5 hours, then hourly for 8 hours was measured. Pain intensity was rated hourly on a scale of 1 to 5 (1 = no pain; 2 = mild pain; 3 = moderate pain; 4 = severe pain; 5 = very severe pain); reported SPID scores were used to calculate 'Adequate pain relief as reported by the woman' (taken over 6 hours) Pain relief was rated hourly on a scale of 1 to 5 (1 = complete; 2 = a lot; 3 = some; 4 = little; 5 = no relief); reported TOTPAR scores were reported Women provided their opinion of the medication on a scale 1 to 4 (1 = excellent; 2 = good; 3 = fair; 4 = poor); ratings of excellent and good were also reported Maternal adverse effects: patient complaints were reported
Notes	Funding: not reported Declarations of interests: not reported Additional arms: this was a 4‐arm trial also assessed etodolac 25 mg (N = 40)and 100 mg (N = 40); we have only included the relevant arms in this review.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "were randomly assigned"
Allocation concealment (selection bias)	Unclear risk	Not detailed
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Described as "double‐blind" but no description of whether the study medications were identical in appearance, taste, etc
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not detailed
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No losses/exclusions reported, but %/no of women ‘remaining in study’ at 4, 6 and 8 hours reported
Selective reporting (reporting bias)	Unclear risk	No access to trial registration or protocol to further assess selective reporting
Other bias	Unclear risk	Results report patients were "well matched" for a variety of baseline characteristics, but no table of these characteristics presented