Accepted for Publication: November 13, 2012, 2013.
Author Contributions: All authors had full access to the data in this report and take responsibility for its integrity and the accuracy of the analysis. Study concept and design: Chren. Acquisition of data: Stuart and Chren. Analysis and interpretation of data: Hamilton and Parvataneni. Drafting of the manuscript: Hamilton and Chren. Critical revision of the manuscript for important intellectual content: All authors. Statistical analysis: Hamilton, Parvataneni, and Chren. Obtained funding: Chren. Administrative, technical, and material support: Stuart. Study supervision: Hamilton and Chren.
Conflict of Interest Disclosures: Dr Chren is a consultant for Genentech Inc.
Funding/Support: This work was supported by grants from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health (grant No. K24 AR052667).