1. Leonard D. Schaeffer Center for Health Policy and Economics, University of Southern California, Los Angeles, California;
2. RAND Corporation, Santa Monica, California;
3. Division of General Pediatrics, Boston Children’s Hospital, Boston, Massachusetts;
4. Department of Pediatrics, Harvard Medical School, Boston, Massachusetts;
5. Departments of Pediatrics, Mattel Children’s Hospital, David Geffen School of Medicine, and
6. Health Policy and Management, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, California