1. 1Rheumatology, Medical Center Leeuwarden, Leeuwarden, The Netherlands
2. Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
3. Rheumatology, Antonius Hospital, Sneek, The Netherlands
4. Rheumatology, MC Groep Hospitals, Lelystad, The Netherlands