1. Department of Medicine, University of Minnesota, Minneapolis, USA
2. Division of General Internal Medicine, University of Minnesota, Minneapolis, USA
3. University of Minnesota Medical School, University of Minnesota, Minneapolis, USA
4. Concordia College, S Moorhead, Minneapolis, USA
5. Biostatistical Design and Analysis Center, Clinical and Translational Science Institute, University of Minnesota, Minneapolis, USA
6. Division of Rheumatic and Autoimmune Diseases, University of Minnesota, Minneapolis, USA
7. Department of Medicine and Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, USA
8. Center for Care Delivery and Outcome Research, Minneapolis VA Health Care System, Minneapolis, USA