Diener 1999.

Methods	Multicentre, randomised, double‐blind, double‐dummy, placebo‐controlled, parallel‐group. Single dose to treat single attack. Medication administered when migraine headache pain was of moderate or severe intensity Assessment at 0.5, 1, 1.5, and 2 h after dosing Rescue medication available after 2 h
Participants	Aged 18 to 65 years, meeting IHS criteria for migraine (1988) with or without aura. At least 1‐year history of migraine (untreated severity ≥ moderate) with an average of 2 to 6 attacks per month. No analgesics or migraine drugs within 24 h of study medication administration. No use of compound analgesics, sumatriptan, ergotamine tartrate, DHE, codeine, or barbiturates for more than 10 days per month prior to screening. N = 278 (275 for efficacy) M 55, F 220 (80%) Mean age 41 years Without aura 67%
Interventions	Sumatriptan 6 mg, n = 114 Intravenous acetylsalicylic acid lysinate 1.8 g, n = 119 Placebo, n = 42
Outcomes	Headache relief (at 1 and 2 h) Pain‐free (at 2 h) Improvement in nausea, vomiting, photophobia, and phonophobia at 2 h Use of rescue medication Adverse events Withdrawals
Notes	Oxford Quality Score: R1, DB2, W1. Total = 4.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐dummy
Study size	High risk	Treatment groups 50 to 200 participants, placebo group < 50 participants