[1] Univ Oslo, Fac Med, Dept Anaesthesiol, Rikshosp, N-0027 Oslo, Norway
[2] Univ Hosp, Rikshosp, Dept Anaesthesiol, Oslo, Norway
[3] Shaare Zedek Med Ctr, Canc Pain & Palliat Med Serv, Jerusalem, Israel
[4] Univ Hosp Leicester NHS Trust, Pain Management Serv, Leicester, Leics, England
[5] Natl Canc Inst Fdn, Rehabil & Palliat Care Unit, Milan, Italy
[6] HCL CHU Lyon, Ctr Hosp Lyon Sud, Ctr Soins Palliatifs, Pierre Benite, France
[7] Erasmushogesch, Dept Gezondheidszorg, Brussels, Belgium
[8] Mundipharma Int Ltd, Cambridge, England