1. aFetal and Neonatal Medicine Institute, Division of Neonatal Medicine, Children’s Hospital Los Angeles, Keck School of Medicine
2. bLeonard D. Schaeffer Center for Health Policy and Economics, University of Southern California, Los Angeles, California
3. cDivision of Neonatology, Department of Pediatrics, Oregon Health Sciences University, Portland, Oregon
4. dDepartment of Neonatology, Beth Israel Deaconess Medical Center, Boston, Massachussetts