NCT02183688.

Methods	Randomised, double‐blind, placebo‐controlled, parallel‐group study
Participants	Migraine or tension‐type headache (IHS). History ≥ 1 year, ≥ 2 episodes per month in previous 3 months, usually treated successfully with non‐prescription analgesics N = 1889 Age 18 to 65 years M and F
Interventions	Low dose aspirin + low dose paracetamol + caffeine Low dose aspirin + low dose paracetamol High dose aspirin High dose paracetamol Caffeine Placebo
Outcomes	50% pain relief at 0.5, 1, 2, 3, and 4 h %max SPID Impairment of daily activities (4‐point scale) Patient global assessment of efficacy (4‐point scale) Adverse events
Notes	Completed; estimated final collection date for primary outcome January 2003 Sponsor: Boehringer Ingelheim

F: female; IHS: International Headache Society; M: male; N: number of participants in study; SPID: weighted sum of pain intensity difference; SPRID: weighted sum of pain relief and pain intensity difference