1. Division of General Internal Medicine, Denver Health and Hospital Authority, Denver, Colorado, USA.
2. Department of Medicine, University of Colorado, Aurora, Colorado, USA.
3. Lehigh Valley Health Network, Allentown, Pennsylvania, USA.
4. Palo Alto Medical Foundation Medical Group, San Carlos, California, USA.
5. School of Medicine, University of California San Francisco, San Francisco, California, USA.
6. San Francisco Veterans Affairs Health Care System, San Francisco, California, USA.
7. Department of Medicine, University of California San Francisco, San Francisco, California, USA.