[1] Icahn Sch Med Mt Sinai, Dept Pain Med & Palliat Care, Mt Sinai Beth Israel, New York, NY 10003 USA
[2] Icahn Sch Med Mt Sinai, Dept Neurol, Headache Program, Mt Sinai Beth Israel, New York, NY 10003 USA
[3] Univ Copenhagen, Danish Headache Ctr, DK-1168 Copenhagen, Denmark
[4] Univ Copenhagen, Dept Neurol, DK-1168 Copenhagen, Denmark
[5] Capital Reg Denmark, Unit Qual & Patient Safety, Hovedstaden, Denmark
[6] Montefiore Headache Ctr, Dept Neurol, Bronx, NY USA
[7] Albert Einstein Coll Med, Dept Epidemiol & Populat Hlth, Bronx, NY USA