Accepted for Publication: February 6, 2013.
Published Online: August 26, 2013. doi:10.1001/jamapediatrics.2013.2204.
Acquisition of data: Sanderson.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: Sanderson, Zurakowski.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Zurakowski.
Administrative, technical, and material support: Sanderson.
Study supervision: Wolfe.
Conflict of Interest Disclosure: None reported.