1. Headache Group, Wolfson CARD, SLaM Biomedical Research Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London and NIHR-Wellcome Trust King’s Clinical Research Facility, King's College Hospital, London, United Kingdom
2. Danish Headache Center, Department of Neurology, Rigshospitalet Glostrup, Denmark
3. Institute for Medical Informatics, Biometry and Epidemiology, University Hospital Essen, Germany
4. The George Institute for Global Health, University of New South Wales, Sydney, Australia
5. Headache Department, Neuroscience Unit, Conci·Carpinella Institute, Córdoba, Argentina
6. Department of Neurology, University of California, Los Angeles, CA, United States
7. Headache Science Center, C. Mondino Foundation, Pavia, Italy
8. University of Pavia, Department of Brain and Behavioral Sciences, Pavia, Italy