1. Department of Community Medicine, West Virginia University, Morgantown, WV, USA
2. West Virginia University, Injury Control Research Center, Morgantown, WV, USA
3. Department of Sociology and Anthropology, North Carolina State University, Raleigh, NC, USA
4. University of North Carolina, Injury Prevention Research Center, Chapel Hill, NC, USA
5. Department of Health Behavior and Health Education, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
6. Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
7. Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA