Accepted for Publication: April 26, 2012.
Published Online: July 23, 2012. doi:10.1001/archinternmed.2012.2606
Author Contributions: Dr Chen 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: Chen, Render, Sales, and Hofer. Acquisition of data: Chen, Render, Sales, Wiitala, and Hofer. Analysis and interpretation of data: Chen, Render, Sales, Kennedy, Wiitala, and Hofer. Drafting of the manuscript: Chen, Render, Sales, Kennedy, and Hofer. Critical revision of the manuscript for important intellectual content: Chen, Render, Sales, Kennedy, Wiitala, and Hofer. Statistical analysis: Chen, Render, Sales, Kennedy, Wiitala, and Hofer. Obtained funding: Render. Administrative, technical, or material support: Render and Wiitala. Study supervision: Render and Hofer.
Financial Disclosure: None reported.
Funding/Support: This material is the result of work supported with resources from the Veterans Affairs Health Services Research and Development Center of Excellence, Veterans Affairs Ann Arbor Healthcare System.
Disclaimer: The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs or the University of Michigan.
Additional Contributions: Eve Kerr, MD, MPH, reviewed an earlier version of the manuscript.