Published Online: November 26, 2014. doi:10.1001/jamasurg.2014.504.
Study concept and design: All authors.
Acquisition, analysis, or interpretation of data: Wu.
Drafting of the manuscript: Wu, Katz.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Wu.
Administrative, technical, or material support: Weaver.
Study supervision: Katz.
Conflict of Interest Disclosures: None reported.
Disclaimer: The American College of Surgeons National Surgical Quality Improvement Program and the participating hospitals are the sources of the data used herein; they have not verified and are not responsible for the statistical validity of the data analysis or the conclusions derived by the authors.
Previous Presentation: This paper was presented at the 85th Annual Meeting of the Pacific Coast Surgical Association; February 15, 2014; Dana Point, California.