From the ∗Department of Pediatrics, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania
†Department of Pediatrics, Nemours/A. I. duPont Hospital for Children, Wilmington, Delaware
‡Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center
§Children’s Hospital of Pittsburgh of University of Pittsburgh Medical Center
∥Department of Statistics, University of Pittsburgh
¶Department of Pediatrics, University of Pittsburgh School of Medicine and Children’s Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
Correspondence: Michael D. Fox, MD, Nemours/A. I. duPont Hospital for Children, 1600 Rockland Rd, Diagnostic Referral Division, Wilmington, DE 19803 (e-mail: [email protected]).
This study was considered exempt by the institutional review board at the University of Pittsburgh.
The authors disclose no conflict of interest.