Published Online: September 29, 2014. doi:10.1001/jamapediatrics.2014.1582.
Study concept and design: All authors.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Dooling, Van Beneden, Hicks.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Shapiro, Hersh.
Administrative, technical, or material support: Dooling.
Study supervision: Van Beneden, Hersh, Hicks.
Conflict of Interest Disclosures: None reported.