1. Department of Emergency Medicine, Brigham & Women’s Hospital, Boston, Massachusetts;
2. Division of Emergency Medicine, and
3. Mayerson Center for Safe & Healthy Children, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio;
4. Department of Pediatrics, Children’s Health Services Research, Indianapolis, Indiana; and
5. Clinical Research Program, Children’s Hospital Boston, Boston, Massachusetts;
6. Department of Pediatrics, Children’s Hospital Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania