1. Center for Health Services Research, Department of Family Medicine, The Larner College of Medicine, University of Vermont, Burlington
2. Department of Emergency Medicine, Massachusetts General Hospital, Boston
3. Department of Neurology, Harvard Medical School, Boston, Massachusetts
4. Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts
5. Harvard T. H. Chan School of Public Health, Boston, Massachusetts
6. Harvard University, Cambridge, Massachusetts
7. Department of Emergency Medicine, Harvard Medical School, Boston, Massachusetts
8. RAND Corporation, Arlington, Virginia
9. Beth Israel Deaconess Medical Center, Boston, Massachusetts