Published Online: March 11, 2013. doi:10.1001/jamainternmed.2013.2797
Author Contributions:Study concept and design: Johansen, Gold, and Green. Acquisition of data: Johansen and Arato. Analysis and interpretation of data: Johansen, Gold, Sen, and Green. Drafting of the manuscript: Johansen, Sen, Arato, and Green. Critical revision of the manuscript for important intellectual content: Johansen, Gold, and Sen. Statistical analysis: Johansen, Sen, and Green. Obtained funding: Johansen and Green. Administrative, technical, and material support: Johansen and Arato. Study supervision: Johansen, Gold, Arato, and Green.
Conflict of Interest Disclosures: None reported.
Funding/Support: This work was supported by grant G1001RR from the American Academy of Family Physicians.
Previous Presentation: These data were presented as a poster at the North American Primary Research Group meeting; November 21, 2011; Banff, Alberta, Canada.