[1] Albert Einstein Coll Med, 1300 Morris Pk Ave,Van Etten 3C12, Bronx, NY 10461 USA
[2] Univ Sheffield, ScHARR, Sheffield, S Yorkshire, England
[3] Univ York, Ctr Hlth Econ, York, N Yorkshire, England
[4] Delta Hat Ltd, Nottingham, England
[5] Amgen Europe GmbH, Econ Modeling Ctr Excellence, Global Hlth Econ, Zug, Switzerland
[6] Amgen Inc, Global Hlth Econ, Thousand Oaks, CA 91320 USA
[7] Dartmouth Hitchcock Med Ctr, Geisel Sch Med Dartmouth, Headache Ctr, Dept Neurol, 1 Med Ctr Dr, Lebanon, NH 03766 USA
[8] Mayo Clin, Scottsdale, AZ USA