Okun 1982.

Study characteristics
Methods	Multi‐arm RCT ‐ 5 groups
Participants	Hospitalised women within 48hrs of birth and with moderate, severe or very severe uterine or episiotomy pain Department of Clinical Pharmacology, Cedars‐Sinai Medical Center, Los Angeles, USA Women who were breast feeding, and/or had received any analgesic, sedative or psychotropic medication within 6 hrs of the study were excluded
Interventions	Interventions: fendosal 100 mg (N = 19), fendosal 200 mg (N = 19), fendosal 400 mg (N = 18) and aspirin 650 mg (N = 20) Control: placebo (N = 18)
Outcomes	Adverse effects Pain intensity difference (PID) Pain relief Requiring additional analgesia Pain intensity was measured on a 5‐point scale of 1 = no pain, 2 = mild pain, 3 = moderate pain, 4 = severe pain and 5 = very severe pain, just before and then hourly from drug administration up to 8 hours, which was the study period. Participants were questioned at 1 and 2 hours whether their pain relief was 50% or greater
Notes	Results are extractable for 8 hours after the intervention only 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
Allocation concealment (selection bias)	Unclear risk	States only that the capsules were identical looking; unclear if numbered sequentially or coded
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	1 nurse observer measured the outcomes, but it is not clear if the observer was blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing or incomplete data
Selective reporting (reporting bias)	Low risk	Outcomes prespecified in the study methods are all reported
Other bias	Low risk	Mean ages, body weights, and pain intensity and type of pain at baseline were comparable across the 5 groups