1. Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
2. Department of Epidemiology, Emory University, Atlanta, GA
3. Department of Medicine, University of Minnesota, Minneapolis, MN
4. Department of Emergency Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
5. Department of Medicine, Wake Forest School of Medicine, Winston-Salem, NC
6. School of Medicine, Indiana University, Indianapolis, IN
7. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC