Accepted for Publication: July 19, 2010.
Author Contributions:Study concept and design: Kaplan, Shaheen, Nguyen, Dixon, and Myers. Acquisition of data: Kaplan. Analysis and interpretation of data: Kaplan, Hubbard, Panaccione, Quan, Ghosh, and Myers. Drafting of the manuscript: Kaplan, Hubbard, and Ghosh. Critical revision of the manuscript for important intellectual content: Kaplan, Hubbard, Panaccione, Shaheen, Quan, Nguyen, Dixon, and Myers. Statistical analysis: Kaplan, Hubbard, Shaheen, Nguyen, Dixon, and Myers. Administrative, technical, and material support: Kaplan. Study supervision: Kaplan, Panaccione, and Ghosh.
Financial Disclosure: None reported.
Funding/Support: This study was supported by grant 848 from the Medical Services Incorporation Foundation, a New Investigator Award from the Canadian Institute of Health Research (Dr Kaplan), and a Population Health Investigator Award from the Alberta Heritage Foundation for Medical Research (Dr Kaplan).