1. Departments of Pediatrics, and
2. Leonard Davis Institute of Health Economics, and
3. Department of Biostatics and Epidemiology, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania;
4. Center for Population Health Information Technology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; and
5. Surgery, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania;
6. Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio