1. Division of Neonatology, Department of Pediatrics, University of California, San Francisco, California;
2. California Perinatal Quality Care Collaborative, Stanford, California;
3. Division of Neonatal-Perinatal Medicine, Department of Pediatrics, and
4. Center for Clinical Research and Evidence-Based Medicine, University of Texas Medical School at Houston, Houston, Texas;
5. Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University, Stanford, California; and
6. Statistics Research Division, Research Triangle Institute, Research Triangle Park, North Carolina