1. Department of Medicine, University of Minnesota , Minneapolis, MN 55455 , USA
2. Division of Epidemiology & Community Health, School of Public Health, University of Minnesota , Minneapolis, MN 55455 , USA
3. Center for Care Delivery and Outcomes Research, VA Health Care System , Minneapolis, MN 55417 , USA
4. California Pacific Medical Center Research Institute , San Francisco, CA 94107 , USA
5. Department of Medicine, University of California, Los Angeles , CA 90095 , USA
6. Bone and Mineral Unit, Oregon Health & Science University , Portland, OR 97239 , USA
7. HealthPartners Institute , Bloomington, MN 55425 , USA
8. Division of Health Policy & Management, School of Public Health, University of Minnesota , Minneapolis, MN 55455 , USA
9. Geriatric Research Education and Clinical Center, VA Health Care System , Minneapolis, MN 55417 , USA
10. Department of Internal Medicine, University of California – Davis , Sacramento, CA 95817 , USA
11. Department of Medicine, Stanford University , Stanford, CA 94304 , USA
12. Geriatric Research Education and Clinical Center, VA Health Care System , Palo Alto, CA 94304 , USA
13. Department of Epidemiology, University of Pittsburgh , Pittsburgh, PA 15261 , USA