Pain 2012 Mar 20;153(3):696-703. Epub 2012 Jan 20.
European Palliative Care Research Centre, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway Department of Oncology, Trondheim University Hospital, Trondheim, Norway Palliative Care, Pain Therapy and Rehabilitation Unit, Fondazione IRCCS (Istituto di Ricovero e Cura a Carraterre Scientifico [Italian Research Hospital]), Istituto Nazionale Dei Tumori, Milano, Italy Department of Anesthesiology and Emergency Medicine, Intensive Care Unit, Trondheim University Hospital, Trondheim, Norway Faculty of Medicine, University of Oslo, Oslo, Norway Regional Center for Excellence in Palliative Care, Oslo University Hospital, Oslo, Norway Scientific Directorate, IRCCS Arcispedale Santa Maria Nuova, Reggio-Emilia, Italy Center for the Evaluation and Research on Pain, Department of Oncology, Instituto di Ricerche Farmacologiche 'Mario Negri', Milan, Italy Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian Univeristy of Science and Technology, Trondheim, Norway.