1. National Registry of Emergency Medical Technicians Columbus Ohio USA
2. Division of Epidemiology The Ohio State University College of Public Health Columbus Ohio USA
3. Division of Biostatistics The Ohio State University College of Public Health Columbus Ohio USA
4. Division of Health Behavior and Health Promotion The Ohio State University College of Public Health Columbus Ohio USA
5. Department of Emergency Medicine Massachusetts General Hospital Harvard Medical School Boston Massachusetts USA
6. Department of Emergency Medicine The Ohio State University Wexner Medical Center Columbus Ohio USA