1. University of North Carolina Department of Epidemiology, Gillings School of Global Public Health, , Chapel Hill, NC 27599-7435, United States
2. University of North Carolina Injury Prevention Research Center, , Chapel Hill, NC 27599, United States
3. University of North Carolina Department of Health Behavior, Gillings School of Global Public Health, , Chapel Hill, NC 27599-7440, United States
4. University of New Mexico Prevention Research Center, Department of Pediatrics, Health Sciences Center, , Albuquerque, NM 87131, United States
5. University of Pennsylvania Penn Injury Science Center, Perelman School of Medicine, , Philadelphia, PA 19104-6021, United States
6. University of Arkansas Center for Public Health and Technology, Department of Health, Human Performance and Recreation, , Fayetteville, AR 72701, United States