Dreiser 1990.

Methods	R, DB, PC, parallel groups Gel lightly massaged into skin over affected area 3 times daily, then covered with standard compress Assessed at baseline, 3, 7 days
Participants	Uncomplicated, ankle sprain (< 4 days) N = 60 (59 analysed) M 29, F 29 (not stated for 1 participant) Mean age 33 years Baseline pain ≥ moderately severe Exclusions: 1 participant had only moderate pain at baseline
Interventions	Niflumic acid gel 2.5%, 3 x 5 g daily, n = 30 Placebo gel, n = 30 Concomitant treatment with systemic NSAIDs, local therapies, or physiotherapy were not allowed
Outcomes	PGE: 4‐point scale (responder = "cured" or "improved") Improvement in pain: VAS (mean data) Adverse events Withdrawals and exclusions
Notes	Oxford Quality Score: R1, DB1, W1. Total = 3/5
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	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants included in analysis
Size	High risk	< 50 participants per treatment arm