1. Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
2. Department of Medicine, Division of General Internal Medicine and Health Services Research, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
3. University of California, Los Angeles, California, USA
4. Department of Medicine, Quality, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
5. Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA