Sait Ashina1, Lars Bendtsen2, Ann C Lyngberg3, Richard B Lipton4, Nazrin Hajiyeva5, Rigmor Jensen2. 1. Department of Pain Medicine and Palliative Care, Mount Sinai Beth Israel, Icahn School of Medicine at Mount Sinai, NY, USA Department of Neurology, Headache Program, Mount Sinai Beth Israel, Icahn School of Medicine at Mount Sinai, NY, USA Danish Headache Center and Department of Neurology, University of Copenhagen, Glostrup Hospital, Denmark sashina@chpnet.org. 2. Danish Headache Center and Department of Neurology, University of Copenhagen, Glostrup Hospital, Denmark. 3. Unit for Quality and Patient Safety, Capital Region of Denmark, Denmark. 4. Department of Neurology, Montefiore Headache Center, and Department of Epidemiology and Population Health, Albert Einstein College of Medicine, NY, USA. 5. Department of Pain Medicine and Palliative Care, Mount Sinai Beth Israel, Icahn School of Medicine at Mount Sinai, NY, USA.