1. Department of Global Public Health and Primary Care, Faculty of Medicine, University of Bergen, Bergen, Norway
2. Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark
3. Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
4. Bergen Group of Epidemiology and Biomarkers in Rheumatic Disease, Department of Rheumatology, Haukeland University Hospital, Bergen, Norway