Accepted for Publication: May 25, 2011.
Author Contributions: Dr Loo had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Loo, Lipsitz, Bates, Agarwal, Markson, and Hamel. Acquisition of data: Loo, Irish, and Markson. Analysis and interpretation of data: Loo, Davis, Lipsitz, Irish, Markson, and Hamel. Drafting of the manuscript: Loo, Lipsitz, and Hamel. Critical revision of the manuscript for important intellectual content: Loo, Davis, Irish, Bates, Agarwal, Markson, and Hamel. Statistical analysis: Davis and Irish. Obtained funding: Lipsitz, Bates, and Agarwal. Administrative, technical, and material support: Loo, Lipsitz, Irish, and Markson. Study supervision: Loo, Lipsitz, and Hamel.
Financial Disclosure: None reported.
Funding/Support: This study was supported by the Donald W. Reynolds Foundation.
Additional Contributions: Russell Phillips, MD, provided guidance and support, and Carolyn Conti, BCS, provided expertise in data management.