1 Division of General Internal Medicine and Health Services Research, UCLA David Geffen School of Medicine, Los Angeles, CA, USA. emshannon@mednet.ucla.edu.
2 Division of General Internal Medicine and Health Services Research, UCLA David Geffen School of Medicine, Los Angeles, CA, USA.
3 Department of Epidemiology, UCLA Fielding School of Public Health, Los Angeles, CA, USA.
4 UCLA Health, Los Angeles, CA, USA.
5 Department of Emergency Medicine, UCLA David Geffen School of Medicine, Los Angeles, CA, USA.