Saillant 1998.

Methods	R, DB, PC, parallel groups Treatment for 7 days Assessed at baseline, 1, 2, 3, and 7 days
Participants	Ankle sprain (< 48 hours) N = 140 M 72, F 62 Age 18 to 65 years Baseline spontaneous pain ≥ 50 mm
Interventions	(1) DHEP plaster (Flector Tissugel 1%), 1 x daily, n = 70 (2) Placebo plaster, 1 x daily, n = 70 Rescue medication: paracetamol (to maximum 3 g daily) Ice allowed
Outcomes	≥ 30% decrease in PI at 7 days PGE: 4‐point scale (responder = "excellent") No or low pain on passive stretch Single foot leaning OK without pain Withdrawals
Notes	Oxford Quality Score: R1, DB2, W1. Total = 4/5
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	Low risk	Identical in size, appearance, and used same formula as active patch, without active ingredient
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Used LOCF for primary outcome. Withdrawals < 7% and equal between groups. All participants included in analysis
Size	Unclear risk	50 to 200 participants per treatment arm