1. Department of Emergency Medicine, University of Michigan, Ann Arbor, Michigan
2. Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan
3. Max Harry Weil Institute for Critical Care Research and Innovation, Ann Arbor, Michigan
4. Department of Geography and Geographic Information System, The University of Cincinnati, Cincinnati, Ohio
5. Department of Emergency Medicine, University of Cincinnati, Cincinnati, Ohio
6. Department of Emergency Medicine, Division of Critical Care, Oregon Health and Science University, Portland, Oregon
7. The Carl and Edyth Lindner Center for Research and Education, The Christ Hospital, Cincinnati, Ohio
8. Department of Emergency Medicine, The University of Maryland, College Park, Maryland
9. AirLift Northwest, University of Washington, Seattle, Washington
10. Department of Emergency Medicine, University of Utah, Salt Lake City, Utah
11. Department of Emergency Medicine & Division of Pulmonary, Critical Care, and Sleep Medicine, University of Washington, Seattle, Washington
12. UC Health, Air Care and Mobile Care, Cincinnati, Ohio
13. University of Cincinnati Libraries, The University of Cincinnati, Cincinnati, Ohio
14. The Cardiac Arrest Registry to Enhance Survival, Atlanta, Georgia
15. Center for Resuscitation Medicine, The University of Minnesota, Minneapolis, Minnesota
16. Department of Surgery, University of Michigan, Ann Arbor, Michigan