Author Contributions:Study concept and design: Levy and Rigotti. Acquisition of data: Levy, Kang, and Vogeli. Analysis and interpretation of data: Levy, Kang, and Rigotti. Drafting of the manuscript: Levy. Critical revision of the manuscript for important intellectual content: Levy, Kang, Vogeli, and Rigotti. Statistical analysis: Levy and Kang. Obtained funding: Levy. Administrative, technical, and material support: Levy and Kang. Study supervision: Levy and Rigotti.
Financial Disclosure: None reported.
Funding/Support: This work was supported by a grant from the Robert Wood Johnson Foundation Substance Abuse Policy Research Program. We acknowledge the assistance of the Illinois Foundation for Quality Health Care and the Centers for Medicare & Medicaid Services (CMS) in providing data which made this research possible.
Disclaimer: The conclusions presented are solely those of the author and do not represent those of Illinois Foundation for Quality Health Care or CMS.
Previous Presentation: This study was presented at the Academy Health Annual Research Meeting; June 27, 2010; Boston, Massachusetts.