1. Clinical Research, Investigation, and Systems Modeling of Acute Illness Laboratory, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
2. Pediatric Heart Lung Center, University of Colorado School of Medicine/Children's Hospital, Denver, Colorado
3. Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
4. Department of Pediatrics, Ohio State University School of Medicine, Columbus, Ohio
5. Research Institute of Nationwide Children's Hospital, Columbus, Ohio
6. Department of Biostatistics, University of Alabama, Birmingham, Alabama
7. ZD Associates, Perkasie, Pennsylvania