Calhoun 2014.

Study characteristics
Methods	Single centre, R, DB, PC, cross‐over study 4 non‐menstrual migraines treated with single dose of study medication (4 sumatriptan plus naproxen, 1 placebo, in random order), within 30 min of onset of headache or neck pain, and only if preceding day was free of both headache and neck pain
Participants	Episodic migraine ± aura (IHS 2004), aged 18 to 55 years. 1‐year history, with 2 to 7 attacks per month in previous 3 months, able to recognise in mild pain stage. Preventive medication stable for previous 2 months and throughout study Excluded: ≥ 8 migraine attacks per month or > 15 days per month of headache or neck pain, uncontrolled hypertension, cardio‐ or cerebrovascular disease, peripheral vascular disease, using MAOI, ergot, SJW N = 43 F = 95% Mean age 36 years
Interventions	Sumatriptan 85 mg plus naproxen 500 mg, n = 43 Placebo n = 43 Rescue medication allowed with open label sumatriptan plus naproxen or other approved medication after 2 h for inadequate response
Outcomes	Pain‐free at 2 h 24‐h sustained pain‐free Adverse events
Notes	Oxford Quality Score: R2, DB1, W0. Total = 3 Authors were contacted to find out what denominator was used to calculate response rate, but the information was not provided
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Study drug and placebo were dispensed based on a randomization code"
Allocation concealment (selection bias)	Unclear risk	Method not described
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Method to maintain blinding not described: "blister pack containing 4 pills", but unclear if pills were identical
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Results reported for ITT population, but it was unclear whether the denominator used to calculate per cent response was participants or headache episodes (each participant was asked to treat 4 episodes)
Study size	High risk	< 50 participants per treatment arm