Author Contributions: Dr Cameron had full access to all of 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: Cameron, Persell, Brown, and Baker. Acquisition of data: Brown, Thompson, and Baker. Analysis and interpretation of data: Cameron, Persell, Thompson, and Baker. Drafting of the manuscript: Cameron and Brown. Critical revision of the manuscript for important intellectual content: Cameron, Persell, Thompson, and Baker. Statistical analysis: Cameron, Persell, and Thompson. Obtained funding: Baker. Administrative, technical, and material support: Brown and Baker. Study supervision: Cameron, Persell, and Baker.