Lene Kristin Brekke1, Bjørg-Tilde Fevang2, Geirmund Myklebust3. 1. Hospital for Rheumatic Diseases, Haugesund, and Department of Clinical Science, University of Bergen, and Bergen Group of Epidemiology and Biomarkers in Rheumatic Disease (BEaBIRD), Department of Rheumatology, Haukeland University Hospital, Bergen; lene.kristin.brekke@hsr.as. 2. Department of Clinical Science, University of Bergen, and BEaBIRD, Department of Rheumatology, Haukeland University Hospital, Bergen. 3. Department of Rheumatology, Hospital of Southern Norway, Kristiansand, Norway.