1. Departmemt of Rheumatology, Diakonhjemmet Hospital, Oslo, Norway
2. Medical Faculty, University of Oslo, Oslo, Norway
3. Department of Rheumatology, Svendborg Hospital, Svendborg, Denmark
4. Department of Rheumatology, Kiljava Medical Research, Hyvinkää, Finland
5. Department of Rheumatology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
6. Department of Rheumatology, Linköping University Hospital, Linköping, Sweden
7. Roche A/S, Hvidovre, Denmark
8. Department of Rheumatology, Rigshospitalet Glostrup, Copenhagen, Denmark