1. Center for Healthcare Research in Pediatrics, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts;
2. Divisions of Infectious Diseases and
3. Department of Biostatistics and Epidemiology, University of Massachusetts Amherst School of Public Health and Health Sciences, Amherst, Massachusetts;
4. Division of Infectious Diseases, Boston Medical Center, Boston, Massachusetts;
5. Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts; and
6. Division of Infectious Diseases and Health Policy Research Institute, University of California, Irvine School of Medicine, Orange, California
7. General Pediatrics, Boston Children’s Hospital, Boston, Massachusetts;