1. Department of Medicine Solna, Clinical Epidemiology Division, Karolinska Institutet , Stockholm, Sweden
2. Division of Rheumatology and Research, Diakonhjemmet Hospital
3. Faculty of Medicine, University of Oslo , Oslo, Norway
4. The DANBIO registry and Copenhagen Center for Arthritis Research (COPECARE), Center for Rheumatology and Spine Diseases, Centre of Head and Orthopaedics, Copenhagen University Hospital Rigshospitalet , Glostrup
5. Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen, Denmark
6. Centre for Rheumatology Research (ICEBIO), Landspitali University Hospital and Faculty of Medicine University of Iceland , Reykjavik, Iceland
7. Division of Rheumatology, Department of Medicine, Hospital of Southern Norway Trust , Kristiansand, Norway
8. Division of Medicine and Rheumatology, Helsinki University Hospital
9. Department of Medicine, University of Helsinki , Helsinki, Finland