This study was sponsored by Grünenthal GmbH, Aachen, Germany. B.M. received honoraria for speaker’s activities for Medscape and Krka and consultancy activities for Reckitt Benckiser, Grünenthal, and Pfizer Belgium. D.A. received honoraria for participation in Advisory Boards and the Change Pain project both with Grünenthal. G.F. and M.Ü. have received funding for a variety of projects from Grünenthal not related to this publication. At the time of the study and during preparation of the manuscript, R.K. was employed by Grünenthal GmbH. Medical writing support was provided by Content Ed Net, with funding from Grünenthal GmbH, Aachen, Germany.