Submitted for Publication: November 10, 2013; final revision received December 20, 2013; accepted January 22, 2014.
Published Online: April 17, 2014. doi:10.1001/jamaoto.2014.417.
Study concept and design: Adams, Singh, Andersen.
Acquisition, analysis, or interpretation of data: Adams, Wilhelm, Singh.
Drafting of the manuscript: Adams, Andersen.
Critical revision of the manuscript for important intellectual content: Adams, Wilhelm, Singh.
Statistical analysis: Adams.
Administrative, technical, or material support: Adams, Wilhelm.
Study supervision: Wilhelm, Singh, Andersen.
Conflict of Interest Disclosures: None reported.