Accepted for Publication: August 1, 2013.
Published Online: April 30, 2014. doi:10.1001/jamasurg.2013.5267.
Study concept and design: Nicol, Knowlton, Schuurman, Matzopoulos, Zargaran, Cinnamon, Taulu, Hameed.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Nicol, Knowlton, Matzopoulos, Hameed.
Critical revision of the manuscript for important intellectual content: Nicol, Knowlton, Schuurman, Matzopoulos, Zargaran, Cinnamon, Fawcett, Hameed.
Statistical analysis: Nicol, Knowlton, Matzopoulos, Hameed.
Obtained funding: Nicol, Schuurman, Zargaran, Fawcett, Hameed.
Administrative, technical, or material support: Nicol, Matzopoulos, Zargaran, Fawcett, Taulu, Hameed.
Study supervision: Nicol, Schuurman, Cinnamon, Taulu, Hameed.
Conflict of Interest Disclosures: None reported.
Funding/Support: This work was supported by the Canadian Institute for Health Research and the Social Sciences and Humanities Research Council.
Role of the Sponsor: The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Contributions: Prestige Makanga, MA, University of Cape Town, assisted with data entry.