Hoffmann 2012.

Methods	R, DB, PC, multicentre, parallel group Plaster applied x 1 daily (minimum of 20 consecutive hours of application per day) for 14 days PI assessed daily, overall efficacy assessed at 7 and 14 days
Participants	Unilateral, mild to moderate muscle contusion of upper or lower limb (< 72 hours), PI ≥ 50/100, superficial haematoma ≤ 10 x 14 cm at injured site N = 354 M 126, F 228 Mean age 39 years
Interventions	DHEP/hep plaster, x 1 daily, n = 121 DHEP plaster, x 1 daily, n = 115 Placebo plaster, n = 118 Rescue medication: paracetamol 500 mg (no limit reported)
Outcomes	PGE: 5‐point scale (responder = excellent or good) at 14 days Mean reduction in PI at 3 and 8 days Rescue medication Adverse events 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	Method not reported
Allocation concealment (selection bias)	Unclear risk	Method not reported: "Medication packed and labelled in order to render all participants and personnel fully blinded to treatment administered"
Blinding (performance bias and detection bias) All outcomes	Low risk	"Indistinguishable regarding appearance, shape, colour, size and odour"
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No responder analysis reported, and imputation method not mentioned
Size	Unclear risk	50 to 200 participants per treatment arm