1. Division of Rheumatology, Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA
2. Internal Medicine Residency Program, Louis A. Weiss Memorial Hospital, Chicago, IL 60640, USA
3. Research Service, Oklahoma City US Department of Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
4. Medicine Service, Oklahoma City US Department of Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
5. Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
6. Arthritis & Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
7. Research Service, Cincinnati US Department of Veterans Affairs Medical Center, Cincinnati, OH 45220, USA
8. Rheumatology Section, Medicine Service, Eastern Colorado Healthcare System, US Department of Veterans Affairs Medical Center, Aurora, CO 80045, USA