1 Department of Emergency Medicine, Vanderbilt University Medical Center, Nashville, TN. Electronic address: [email protected].
2 Department of Emergency Medicine, University of Michigan, Ann Arbor, MI.
3 Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL.
4 Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL; Department of Medicine, University of Western Australia, Perth, WA, Australia.
5 Department of Health Policy, Vanderbilt University Medical Center, Nashville, TN.
6 Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN.