Published Online: June 24, 2015. doi:10.1001/jamasurg.2015.0965.
Study concept and design: Crawford.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Kelley, Johnson.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Kelley, Gardiner.
Administrative, technical, or material support: Crawford, Johnson.
Study supervision: Thomas.
Conflict of Interest Disclosures: None reported.
Previous Presentation: This paper was presented at the 86th Annual Meeting of the Pacific Coast Surgical Association; February 20, 2015; Monterey, California.