Methods	Multicentre, randomised, double-blind, placebo-controlled, two-period cross-over. Single oral dose of each medication for each of two attacks Medication administered when migraine headache pain of moderate or severe intensity Assessments at 0, 0.25, 0.5, 0.75, 1, 2, 3, 4, and 6 hours post-treatment If pain not controlled, participants asked to wait 2 hours before taking rescue medication
Participants	Aged > 18 years, meeting IHS criteria for migraine with and without aura. At least 12-month history of migraine, with one to six attacks per month within previous three months Excluded participants who vomited during the majority of their migraine attacks Excluded participants who regularly used NSAIDs or other drugs that could interact with trial medications N = 101 (73 treated two attacks and analysed for efficacy) M = 11, F = 90 Mean age 44 years
Interventions	Mouth-dispersible aspirin 900 mg, n = 73 Placebo, n = 73
Outcomes	Headache relief at all assessment time points Pain-free at all assessment time points PI: standard 4-point scale Functional disability: standard 4-point scale Presence/absence of associated symptoms Headache recurrence at 24 hours Use of rescue medication Participants’ and investigators’ global assessments Palatability and convenience of study medication
Notes	Oxford Quality Score: R1, DB2, W1. Total score = 4.
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Unclear	Not described
Allocation concealment?	Unclear	Not described
Blinding? All outcomes	Yes	“Placebo tablets formulated and manufactured to be indistinguishable from aspirin tablets, with respect to appearance, taste and dispersion in mouth”