Submitted for Publication: July 21, 2011; accepted September 27, 2011.
Author Contributions: All authors 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: Sharp and Lee. Acquisition of data: Puscas, Sharp, and Lee. Analysis and interpretation of data: Puscas, Sharp, Schwab, and Lee. Drafting of the manuscript: Puscas and Lee. Critical revision of the manuscript for important intellectual content: Sharp, Schwab, and Lee. Statistical analysis: Sharp, Schwab, and Lee. Administrative, technical, and material support: Schwab. Study supervision: Lee.
Financial Disclosure: None reported.
Additional Information: Drs Puscas and Sharp contributed equally to this work.
Additional Contributions: Maragatha Kuchibhatla, PhD, Department of Biostatistics and Bioinformatics, Duke University, performed data analysis. Ramon M. Esclamado, MD, provided intellectual contributions to this project.