Peroutka 2004.

Methods	Single‐centre, randomised, double‐blind, placebo‐controlled, 3‐period cross‐over study Single oral dose administered at the onset of moderate or severe pain Duration: 24 h, with assessments at baseline, 1, 6, and 24 h post dose
Participants	Acute migraine attack without aura, in accordance with IHS criteria, with a history of ≥ 12 months Participants were 18 to 60 years of age N = 72 enrolled (52 treated first attack, 46 treated second attack, 39 treated the third attack); treated a total of 134 attacks M 10, F 62 Mean age 45 years
Interventions	Numbers of attacks treated: Diclofenac sodium softgel 100 mg + caffeine 100 mg, n = 43 Diclofenac sodium softgel 100 mg, n = 46 Placebo, n = 45
Outcomes	Headache relief at 1 h Withdrawals and dropouts Serious adverse events
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	Method used to generate random sequence not described
Allocation concealment (selection bias)	Unclear risk	Method not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Method not described
Size	High risk	< 50 participants in relevant treatment arms