Accepted for Publication: June 21, 2011.
Author Contributions: Dr Sanfey 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: Sanfey, Mellinger, Wohltman, and Dunnington. Acquisition of data: Sanfey, Cofer, Hiatt, Hyser, Jakey, Mellinger, Sidwell, and Smink. Analysis and interpretation of data: Sanfey, Hiatt, Markwell, Mellinger, Smink, and Wise. Drafting of the manuscript: Sanfey. Critical revision of the manuscript for important intellectual content: Sanfey, Cofer, Hiatt, Hyser, Jakey, Markwell, Mellinger, Sidwell, Smink, Wise, Wohltman, and Dunnington. Statistical analysis: Sanfey and Markwell. Administrative, technical, and material support: Cofer, Hyser, and Jakey. Study supervision: Sanfey.
Financial Disclosure: None reported.