Submitted for Publication: April 19, 2012; final revision received June 4, 2012; accepted July 13, 2012.
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: Tanphaichitr, Bhushan, Maddalozzo, and Schroeder. Acquisition of data: Tanphaichitr and Bhushan. Analysis and interpretation of data: Tanphaichitr, Bhushan, and Schroeder. Drafting of the manuscript: Tanphaichitr, Bhushan, and Maddalozzo. Critical revision of the manuscript for important intellectual content: Tanphaichitr and Schroeder. Statistical analysis: Tanphaichitr and Bhushan. Administrative, technical, and material support: Tanphaichitr, Bhushan, Maddalozzo, and Schroeder. Study supervision: Bhushan, Maddalozzo, and Schroeder.
Financial Disclosure: None reported.
Previous Presentation: These data were presented at the ASPO Spring Meeting; April 20, 2012; San Diego, California.