1. Maastricht University Medical Center; Maastricht The Netherlands
2. Amsterdam Medical Center; Amsterdam The Netherlands
3. University of British Columbia and Arthritis Research Centre of Canada; Vancouver British Columbia Canada
4. University Medical Center Groningen, University of Groningen, Groningen, The Netherlands, and Medical Center Leeuwarden; Leeuwarden The Netherlands
5. Leiden University Medical Center; Leiden The Netherlands
6. Sint Laurentius Hospital Roermond, Roermond, The Netherlands, and Sint Jans Gasthuis Weert; Weert The Netherlands
7. Erasmus Medical Center Rotterdam; Rotterdam The Netherlands
8. Dalla Lana School of Public Health, University of Toronto, and Institute for Work and Health; Toronto Ontario Canada
9. Annelies Boonen, MD, PhD, Maastricht University Medical Center and Caphri Research Institute, Maastricht University; Maastricht The Netherlands