1 Division of General Internal Medicine and Health Services Research, Department of Medicine, David Geffen School of Medicine at UCLA, 911 Broxton Avenue #301, Los Angeles, CA, 90024, USA. jmafi@mednet.ucla.edu.
2 RAND Corporation, Santa Monica, CA, USA. jmafi@mednet.ucla.edu.
3 Section of General Internal Medicine, Veterans Affairs Portland Health Care System, Portland, OR, USA.
4 Division of General Internal Medicine and Geriatrics, Oregon Health and Science University, Portland, OR, USA.