1. Department of Emergency Medicine, New York University School of Medicine, New York, New York.
2. Department of Population Health, New York University School of Medicine, New York, New York.
3. Robert Wood Johnson Foundation Clinical Scholars Program, University of Pennsylvania, Philadelphia, Pennsylvania.
4. Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, Pennsylvania.
5. Department of Emergency Medicine, Kimmel School of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania.
6. Emergency Care Coordination Center, Office of the Assistant Secretary for Preparedness and Response, Department of Health and Human Services, Washington, DC.
7. Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania.
8. Department of Sociology, Columbia University, New York, New York.
9. Division of General Internal Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
10. Department of Health Care Management, The Wharton School, University of Pennsylvania, Philadelphia, Pennsylvania.
11. Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania.
12. Cartographic Modeling Laboratory, University of Pennsylvania, Philadelphia, Pennsylvania.