Russell 1991.

Methods	R, DB, PC, parallel groups Affected area washed with soap and water and dried, then gel applied and carefully rubbed into skin, 4 times daily for at least 7 days Assessed at baseline, 4, 8, 15 (if necessary) days at clinic, and daily patient diary
Participants	Acute soft tissue injuries (recent, not recurrent) N = 214 (200 analysed) M 95, F 105 Mean age 40 years Baseline pain > 65 mm
Interventions	Piroxicam gel 0.5%, 4 x 5 mg daily, n = 100 Placebo gel, n = 100 No other NSAIDs or analgesic drugs, including liniments containing salicylates, allowed. Ancillary therapy at the discretion of the investigator
Outcomes	PGE: 4‐point scale (responder = "good" and "excellent") Spontaneous pain: mean reduction Adverse events Withdrawals
Notes	Oxford Quality Score: R2, DB2, W1. Total = 5/5
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"computer generated randomization code"
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	Low risk	"identical base formulation"
Incomplete outcome data (attrition bias) All outcomes	High risk	High withdrawal rate (8% with piroxicam, 50% with placebo). No information about imputation
Size	Unclear risk	50 to 100 participants per treatment group