1. Division of Emergency Medicine, Rady Children's Hospital, University of California San Diego, San Diego, CA, USA;
2. Division of Internal Medicine & Pediatrics, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA;
3. Division of General Internal Medicine and Health Services Research, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA;
4. Department of Pediatrics, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA;
5. Division of Emergency & Transport Medicine, Children’s Hospital Los Angeles, University of Southern California, Los Angeles, CA, USA