1. Leiden University Medical Center; Department of Rheumatology; Albinusdreef 2 Leiden Netherlands 2333 ZA
2. Leiden University Medical Center; Department of Physical Therapy and Occupational Therapy H0-Q; PO Box 9600 Leiden Netherlands 2300 RC
3. Leiden University Medical Center; Department of Rheumatology C4-R; PO Box 9600 Leiden Netherlands 2300 RC
4. Sint Maartenskliniek; Department of Rheumatology; Hengstdal 3 Nijmegen Netherlands 6522 JV