Methods	Multicentre, randomised, double-blind, placebo-controlled, parallel-group Single dose to treat single attack, with the option of a second randomised dose of study medication or placebo if pain relief was inadequate at 1 h Medication administered when migraine headache pain was of moderate or severe intensity Assessments at 10, 20, 30, 40, 50, 60, 90, and 120 minutes after dosing Rescue medication available at the discretion of the investigator if migraine persisted 1 h after second dose of study medication 2 separate identical trials
Participants	Aged 18 years or over, meeting IHS criteria for migraine (1988) with or without aura. At least 1-year history of migraine (untreated severity ≥ moderate) Participants excluded if previously treated with sumatriptan Long-term prophylactic medications for migraine allowed. No opioids or ergotamine within 24 h, or simple analgesics within 6 h of taking study medication Study 1 N= 574 M 73, F 501 (87%) Mean age 40 years Proportion with/without aura not reported Study 2 N = 530 M 53, F 477 (90%) Mean age 39 years Proportion with/without aura not reported
Interventions	Study 1 Sumatriptan 6 mg, n = 384 Placebo, n = 190 Study 2 Sumatriptan 6 mg, n = 350 Placebo, n = 180
Outcomes	All outcomes reported as pooled results from the 2 studies (Study 1 and Study 2) Headache relief (at 1 h) and 2 h (1 h after optional 2nd dose) Pain-free (at 1 h) Improvement in nausea and photophobia at 1 h Improvement in functional disability at 1 h Adverse events Withdrawals
Notes	Oxford Quality Score: R1, DB1, W1. Total = 3.
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Low risk	Allocation based on chronological order that patients presented for treatment
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not reported
Study size	Low risk	Treatment groups > 200 participants