1. The Heart Institute; Cincinnati Children's Hospital Medical Center; Cincinnati Ohio USA
2. The James M. Anderson Center for Clinical Excellence; Cincinnati Children's Hospital Medical Center; Cincinnati Ohio USA
3. Children's Hospital & Medical Center; Omaha Neb USA
4. University of Maryland School of Medicine; Baltimore Md USA
5. Boston Children's Hospital Medical Center; Boston Mass USA
6. Mattel Children's Hospital at UCLA; Los Angeles Calif USA
7. Children's National Medical Center; Washington DC USA
8. University of Texas Health Center; San Antonio Tex USA
9. Division of Biostatistics and Epidemiology; Cincinnati Children's Hospital Medical Center; Cincinnati Ohio USA