1. National Institute of Arthritis and Musculoskeletal and Skin Diseases/NIH Bethesda Maryland
2. Hospital de Santa Maria Lisbon Portugal
3. Mount Sinai Hospital University of Toronto Toronto Ontario Canada
4. University of Oxford Oxford UK
5. University of South Florida Tampa
6. Cleveland Clinic Foundation Cleveland Ohio
7. McMaster University Hamilton Ontario Canada
8. University of Utah Salt Lake City
9. Henry Ford Health System Detroit Michigan
10. University of Pennsylvania Philadelphia
11. Veterans Affairs Boston Healthcare System Boston Massachusetts
12. University of Pittsburgh Pennsylvania
13. National Institute of Arthritis and Musculoskeletal and Skin Diseases/NIH, Bethesda, Maryland, and Georgetown University Washington DC
14. University of the West of England Bristol UK
15. Johns Hopkins University Baltimore Maryland
16. Auckland District Health Board Auckland New Zealand
17. Mayo Clinic Rochester Minnesota
18. Norwich Medical School, University of East Anglia, Norwich, and University of Oxford Oxford UK