1. Vanderbilt Center for Child Health Policy, Vanderbilt University Medical Center, Nashville, Tennessee
2. Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
3. Department of Health Policy, Vanderbilt University Medical Center, Nashville, Tennessee
4. RAND Corporation, Pittsburgh, Pennsylvania
5. Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee
6. Department of Medicine, Division of Infectious Disease, Vanderbilt University Medical Center, Nashville, Tennessee
7. Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, Tennessee
8. University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania