1. Department of Rheumatology, University Hospital Ghent , Ghent, Belgium
2. Department of Internal Medicine and Pediatrics, Faculty of Medicine and Health Sciences, Ghent University , Ghent, Belgium
3. Center for Inflammation Research, VIB-UGent , Zwijnaarde, Belgium
4. Service for benefits, National Institute for Health and Disability Insurance , Brussels, Belgium
5. Department of Internal Medicine, Division of Rheumatology, Maastricht University Medical Center , Maastricht, The Netherlands