Submitted for Publication: June 21, 2013; final revision received September 3, 2013; accepted September 12, 2013.
Published Online: December 12, 2013. doi:10.1001/jamaoto.2013.5991.
Study concept and design: Loehrl, Poetker.
Acquisition of data: Stoddard, Loehrl.
Analysis and interpretation of data: Stoddard, Hunt.
Drafting of the manuscript: Stoddard.
Critical revision of the manuscript for important intellectual content: All authors.
Administrative, technical, or material support: Stoddard.
Study supervision: Loehrl, Poetker.
Conflict of Interest Disclosures: None reported.