1. Università degli Studi di L’Aquila, L’Aquila, Italy
2. Schmerz- und Palliativzentrum, Göppingen, Germany
3. Naples Anesthesia and Pain Associates, Naples, FL, USA
4. Hospicjum Domowe, Wrocław, Poland
5. University Hospitals Leuven, Leuven, Belgium
6. Clinique Cecil, Lausanne, Switzerland
7. Hospital General Universitario de Alicante, Alicante, Spain
8. Hospital Santo André, Leiria, Portugal
9. Wilhelminenspital der Stadt Wien, Vienna, Austria
10. University Hospital Rotterdam, Rotterdam, The Netherlands
11. Leicester Royal Infirmary, Leicester, UK
12. A.O. Ospedaliero-Universitaria Parma, Parma, Italy
13. Churchill Hospital, Oxford, UK
14. Karolinska University Hospital Solna, Solna, Sweden