Accepted for publication: December 22, 2011.
Published Online: March 19, 2012. doi:10.1001/archsurg.2012.96
Author Contributions: Drs Stang, Armstrong, and Carty had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Stang, Ogilvie, and Carty. Acquisition of data: Stang, Armstrong, Ogilvie, and Carty. Analysis and interpretation of data: Stang, Armstrong, Ogilvie, Yip, McCoy, Faber, and Carty. Drafting of the manuscript: Stang, Armstrong, Faber, and Carty. Critical revision of the manuscript for important intellectual content: Stang, Armstrong, Ogilvie, Yip, McCoy, Faber, and Carty. Statistical analysis: Stang and Armstrong. Administrative, technical, and material support: Stang, Armstrong, Yip, McCoy, and Carty. Study supervision: Ogilvie and Carty.
Financial Disclosure: Dr Carty receives royalties as section editor for UpToDate, Inc (online medical textbook).