Sakata 1986

Methods	Randomised, double blind, placebo control, single oral dose. Study duration 4 h Baseline PI = moderate and severe Self assessment at t = 0.30, 1, and then hourly up to 4 h.
Participants	Mainly orthopaedic surgery N = 86 M 49, F 37 Mean age: 32 years
Interventions	Dipyrone 1 g, n = 30 Acetaminophen 1 g, n = 30 Placebo group, n = 30
Outcomes	PI: standard 4 point scale (0‐3) PR: standard 5 point (0‐4) PGE: nonstandard 4 point scale
Notes	Oxford Quality Score: R1, DB1, W0. Total = 2
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not reported