1. Division of Psychosocial Medicine, University Hospital, Zürich, Switzerland; Abteilung für Psychosoziale Medizin, Universitätsspital, Culmannstrasse 8, 8091 Zürich, Switzerland. Tel: (/ 41) 1 255 52 52; Fax: (/ 41) 1 255 43 84;
2. Department of Rheumatology, Inselspital, Bern, Switzerland
3. Rheumaund Rehabilitationsklinik, Schinznach, Switzerland
4. Division of Psychosocial Medicine, University Hospital, Zürich, Switzerland
5. Imperial College of Medicine, West Middlesex University Hospital, London, UK