Olson 1997.

Study characteristics
Methods	RCT
Participants	Setting: Hospital Maternidad Concepcion Palacios, Caracas, Venezuela Trial dates: not reported (published in 1997) Inclusion criteria: women of legal age (aged ≥ 18 years), who were able to communicate meaningfully with the nurse‐observer, who were hospitalised and had severe post‐episiotomy pain after an uncomplicated birth and could tolerate oral medications Exclusion criteria: planning to breast feed within 24 hours after administration of the study medications; serious complicating illness or abnormal postpartum bleeding, with active peptic ulcer disease or other gastrointestinal disease associated with blood loss; receipt of any other investigational drug within the 1 month prior; history of drug or alcohol abuse; known allergic sensitivities to aspirin, diclofenac, or other NSAIDs
Interventions	Aspirin (N = 50 randomised) 650 mg aspirin; single oral dose of 2 x 325 mg capsules; and 3 placebo tablets Placebo (N = 52 randomised) Placebo; single oral dose of 2 placebo capsule and 3 placebo tablets All women: each woman received a single unit dose consisting of 2 capsules and 3 tablets, with at least 8 ounces of water; women were asked to sit up or lie on their right side for 2 hours after administration. No medications (analgesics, sedatives, hypnotics, tranquillisers) were permitted concomitantly or during the 4 hours prior to taking the medication
Outcomes	Adequate pain relief as reported by the woman: the same nurse observer interviewed the women at 0.5 hours, and hourly for 8 hours Women assessed their episiotomy pain on a scale of 0 to 3 (none = 0; slight pain = 1; moderate pain = 2; severe pain = 3); SPID scores were reported, and used to calculate 'Adequate pain relief as reported by the woman' (taken at 4 hours; also reported at 8 hours) Women were asked to classify pain relief on a scale of 0 to 4 (none = 0; a little = 25% = 1; some = 50% = 2; a lot = 75% = 3; complete = 100% = 4; TOTPAR scores were also reported Women were asked to rate the study medication and assess their overall improvement; study medication: 0 = poor; 1 = fair; 2 = good; 3 = excellent; overall improvement: 1 = very much worse; 7 = very much better Need for additional pain relief in the first 48 hours for perineal pain: re‐medication within 8‐hour study period Maternal adverse effects: adverse effects were recorded if they were observed or volunteered
Notes	Funding: "This work was supported in part by a grant from the Ciba‐Geigy Corporation, Summit, NJ" Declarations of interests: not reported; though first and second authors affiliated with "Analgesic Development Ltd." Additional arms: this 5‐arm trial also assessed diclofenac potassium 25 mg (N = 52), 50 mg (N = 50), and 100 mg (N = 51); we only included the relevant arms in this review
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "randomly assigned… computer program generated a random permutation such that two patients received each treatment"
Allocation concealment (selection bias)	Unclear risk	No details provided
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quotes: "double‐blind" and "Each patient received a single‐unit dose consisting of 3 tablets and 2 capsules… all unit doses were identical in appearance and packaging"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	1 nurse observer involved in outcome assessment
Incomplete outcome data (attrition bias) All outcomes	High risk	If a woman wished to withdraw before the first hour because of inadequate relief, a non‐study analgesic was administered, and she was discontinued from the study (none were re‐medicated in this first hour; therefore, no discontinuations); if a woman required additional analgesic after the first hour, she was included, and relief scores of 0, and intensity scores equal to the pain at time of re‐medication were assumed for the duration (5/50 in the aspirin group; 19/52 in the placebo group)
Selective reporting (reporting bias)	Unclear risk	No access to trial protocol to further assess risk of selective reporting
Other bias	Low risk	Baseline characteristics reported (age, weight, height, parity, days post‐delivery) were comparable between groups; no other obvious sources of bias identified