Russell 1994.

Methods	Multicentre, randomised, double‐blind, placebo‐controlled, cross‐over design. Single dose to treat each of 2 successive attacks. Assessments at 1 and 2 h after dosing. Second dose of study medication available after 2 h for participants not completely free from headache, or experiencing recurrence of headache within 24 h Rescue medication (non‐ergotamine) was available 1 h after second injection if symptom relief remained inadequate
Participants	Aged 18 to 65, with GP diagnosed migraine. At least 6‐month history of migraine (untreated severity ≥ moderate) with an average of 1 to 6 attacks per month. Participants were excluded if they had previously used sumatriptan or were currently using migraine prophylactic agents N = 230 (209 treated both attacks) M 20, F 189 (90%) Mean age 44 years Post‐treatment headache diagnosis revealed that ≥ 90% of treated attacks met IHS criteria for migraine (1988) with or without aura. Without aura 65% Approximately 1% of participants had mild baseline pain intensity when study medication was administered
Interventions	Sumatriptan 6 mg, n = 209 Placebo, n = 209
Outcomes	Adverse events
Notes	Oxford Quality Score: R1, DB1, W0. Total = 2.
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	Unclear risk	Not reported
Study size	Low risk	Treatment groups > 200 participants