1. Division of Critical Care, Northwestern University Feinberg School of Medicine and Children's Memorial Hospital, Chicago, Illinois;
2. Child Health Corporation of America, Shawnee Mission, Kansas;
3. Clinical Research, Investigation, and Systems Modeling of Acute Illness Laboratory, Departments of Critical Care Medicine and Pediatrics, University of Pittsburgh School of Medicine and Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania;
4. Department of Pediatrics, Children's Hospital Los Angeles and Keck School of Medicine, University of Southern California, Los Angeles, California;
5. Division of Infectious Diseases, Children's Hospital of Philadelphia and Departments of Pediatrics and Epidemiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania; and
6. Internal Medicine and Pediatrics, Virginia Tech-Carilion School of Medicine, Roanoke, Virginia