1. Geriatric Research Education and Clinical Center; Veterans Affairs Health Center; Minneapolis MN USA
2. Center for Chronic Disease Outcomes Research; Veterans Affairs Health Center; Minneapolis MN USA
3. Department of Medicine, and Division of Epidemiology and Community Health; University of Minnesota; Minneapolis MN USA
4. California Pacific Medical Center Research Institute; San Francisco CA USA
5. Department of Family Medicine and Public Health; University of California; San Diego La Jolla, CA USA
6. Park Nicollet Institute; Minneapolis MN USA
7. Division of Health Policy and Management; University of Minnesota; Minneapolis MN USA
8. Department of Epidemiology and Biostatistics; University of California; San Francisco San Francisco, CA USA
9. Department of Epidemiology; Graduate School of Public Health; University of Pittsburgh; Pittsburgh PA USA
10. Division of Rheumatology, Allergy and Clinical Immunology, Department of Medicine; University of California; Davis Davis, CA USA
11. Department of Orthopaedics and Rehabilitation; Oregon Health and Science University; Portland OR USA