Submitted for Publication: November 20, 2012; final revision received February 20, 2013; accepted April 15, 2013.
Published Online: June 20, 2013. doi:10.1001/jamaoto.2013.3294.
Study concept and design: All authors.
Acquisition of data: Lalwani.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: All authors.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Govil, Liu.
Administrative, technical, and material support: Lalwani.
Study supervision: Weitzman, Lalwani.
Conflict of Interest Disclosures: None reported.
Previous Presentation: This study was presented in part at the Pediatric Academic Societies meeting; April 30, 2012; Boston, Massachusetts.
Correction: This article was corrected online July 23, 2013, for system-generated bracketed text in reference 18.