Published Online: June 1, 2015. doi:10.1001/jamapediatrics.2015.0269.
Study concept and design: All authors.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Randell.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Randell, Dowd.
Administrative, technical, or material support: Dowd.
Study supervision: Dowd.
Conflict of Interest Disclosures: None reported.