Accepted for Publication: April 9, 2013.
Published Online: November 20, 2013. doi:10.1001/jamasurg.2013.2517.
Study concept and design: Emil.
Acquisition of data: Cheong, Emil.
Analysis and interpretation of data: Cheong, Emil.
Drafting of the manuscript: Cheong, Emil.
Critical revision of the manuscript for important intellectual content: Emil.
Statistical analysis: Cheong.
Administrative, technical, or material support: Cheong, Emil.
Study supervision: Emil.
Conflict of Interest Disclosures: None reported.
Previous Presentation: This paper was presented at the 84th annual meeting of the Pacific Coast Surgical Association; February 17, 2013; Kauai, Hawaii; and is published after peer review and revision.
Additional Contributions: We thank Elise Mok, PhD, and Xun Zhang, PhD, of the Montreal Children’s Hospital Clinical Research Center for providing assistance with statistical analysis.