1. University of California, Los Angeles, Ronald Reagan Medical Center, Department of Emergency Medicine, Los Angeles, California; David Geffen School of Medicine at University of California Los Angeles, Department of Emergency Medicine, Los Angeles, California
2. University of Pittsburgh School of Medicine, Department of Emergency Medicine, Pittsburgh, Pennsylvania
3. Central Michigan University Medical Education Partners, Department of Emergency Medicine, Saginaw, Michigan; Central Michigan University College of Medicine, Department of Emergency Medicine, Mt. Pleasant, Michigan
4. Denver Health Medical Center, Department of Emergency Medicine, Denver, Colorado; University of Colorado School of Medicine, Department of Emergency Medicine, Aurora, Colorado