1. Houston VA HSR&D Center for Innovations, Michael E. DeBakey Veterans Affairs Medical Center and the Section of Health Services Research, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
2. UCSF Center for Vulnerable Populations, San Francisco General Hospital, San Francisco, CA, USA
3. Division of General Internal Medicine, Department of Medicine, University of California, San Francisco General Hospital, San Francisco, CA, USA