1. Colorado School of Public Health, Injury and Violence Prevention Center, Aurora, Colorado, USA.
2. Colorado School of Public Health, Biostatistics and Informatics, Aurora, Colorado, USA.
3. Emory University Rollins School of Public Health, Biostatistics and Bioinformatics, Atlanta, Georgia, USA.
4. University of Colorado School of Medicine, Pediatrics-Emergency Medicine, Aurora, Colorado, USA.