1. Department of Pediatrics, Mattel Children's Hospital at UCLA, David Geffen School of Medicine at UCLA, Los Angeles, California
2. RAND Health, RAND Corporation, Santa Monica, California
3. Department of Pediatrics, Evanston Northwestern Healthcare, Feinberg School of Medicine at Northwestern University, Evanston, Illinois
4. Department of Pediatrics, Children's Hospital of Boston, Harvard Medical School, Boston, Massachusetts
5. Department of Health Services, UCLA School of Public Health, Los Angeles, California