Accepted for Publication: April 8, 2014.
Published Online: August 18, 2014. doi:10.1001/jamainternmed.2014.3895.
Study concept and design: Royce, Stokes, Allen, Chen.
Acquisition, analysis, or interpretation of data: Royce, Hendrix, Chen.
Drafting of the manuscript: Royce, Hendrix, Allen, Chen.
Critical revision of the manuscript for important intellectual content: Royce, Stokes, Chen.
Statistical analysis: Royce, Hendrix, Allen.
Obtained funding: Royce.
Administrative, technical, or material support: Royce, Stokes, Allen.
Study supervision: Chen.
Conflict of Interest Disclosures: None reported.
Funding/Support: This work was supported in part by a grant from the Doris Duke Charitable Foundation to the University of North Carolina at Chapel Hill to fund Clinical Research Fellow Dr Royce.
Role of the Sponsor: The Doris Duke Charitable Foundation had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Disclaimer: This study used the National Health Interview Survey (NHIS) database. The interpretation and reporting of these data are the sole responsibility of the authors.
Previous Presentation: The data in the study were presented as an abstract for oral presentation at the Annual Meeting of the American Society for Radiation Oncology; October 28-31, 2012; Boston, Massachusetts.
Additional Contributions: We acknowledge the National Center of Health Statistics in the creation of the NHIS database.