Olson 1999

Methods	Multi‐arm RCT – 4 groups.
Participants	Women 18 years or older and able to communicate meaningfully with nurse‐observer, hospitalised and were in good health, could tolerate oral medication and had severe post‐episiotomy pain after term delivery with no medical complications at Hospital Maternidad Concepcion Palacios, Caracas, Venezuela. Women who were breastfeeding or who planned to breastfeed within 48 hours after drug administration, with none or suspected hypersensitivity to dipyrone, ketoprofen or other NSAID agents or who received any other investigational drug within 1 month prior to enrolment in the study were excluded.
Interventions	Intervention: ketoprofen oral solution 5%, 25 mg prepared in 0.45 mL (N = 28); ketoprofen oral solution 5%, 50 mg prepared in 0.90 mL (N = 26) and dipyrone oral solution 500 mg prepared in 1 mL or 30 drops (N = 27). Comparison: placebo oral solution (N = 27).
Outcomes	Pain intensity (0 = none, 1 = slight, 2 = moderate, 3 = severe). Pain relief (0 = none, 1 = a little (25%), 2 = some (50%), 3 = a lot (75%), 4 = complete (100%)). Additional analgesia (included in analysis if requested after 1 hour). Adverse effects. Global rating of study medication (0 = poor, 1 = fair, 2 = good and 3 = excellent). Pain intensity and relief collected at baseline prior to treatment, at; 15, 30, 60, 90 and 120 minutes after treatment and hourly thereafter for a total of 6 hours.
Notes	Dipyrone oral solution not considered for the review as not NSAID.
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	States individual randomisation envelope was prepared for each patient, and sealed (and opened later by nurse A), but does not state if opaque and consecutively labelled.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Nurse A prepared and gave the medication to the participants, so was aware of their allocation; although Nurse B was the observer and did not know the allocations, there is a risk of bias here as nurse A (although instructed not to disclose drug) could have.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No clear statement.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data provided for all 108 participants (0% attrition rate in all groups).
Selective reporting (reporting bias)	Low risk	Pre‐specified outcomes were all reported.
Other bias	High risk	No significant differences among the treatment groups with respect to characteristics and clinical features; The study, however, was prematurely terminated due to administrative changes; thus less than half of the sample size estimate was recruited.