1. Leiden University Medical Center, Leiden, The Netherlands, and Universidade Nova de Lisboa Lisboa Portugal
2. Leiden University Medical Center, Leiden, The Netherlands, and Zuyderland Medical Center Heerlen The Netherlands
3. University of Alberta and CARE Arthritis Edmonton Alberta Canada
4. Mahidol University Bangkok Thailand
5. CARE Arthritis Edmonton Alberta Canada
6. Leiden University Medical Center Leiden The Netherlands
7. Amsterdam University Medical Center, Amsterdam, The Netherlands, and Zuyderland Medical Center Heerlen the Netherlands