Author Contributions: Dr Wachterman had full access to all of 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: Wachterman, McCarthy.
Acquisition of data: Wachterman, McCarthy.
Analysis and interpretation of data: Wachterman, Marcantonio, Davis, McCarthy.
Drafting of the manuscript: Wachterman, McCarthy.
Critical revision of the manuscript for important intellectual content: Wachterman, Marcantonio, Davis, McCarthy.
Statistical analysis: Wachterman, Davis, McCarthy.
Obtained funding: Wachterman.
Administrative, technical, or material support: Wachterman, Marcantonio, Davis, McCarthy.
Study supervision: Marcantonio, McCarthy.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Funding/Support: Dr Wachterman received support from grant 6T32HP12706-02-01 from the Health Resources and Services Administration of the Department of Health and Human Services to support the Harvard Medical School Fellowship Program in General Medicine and Primary Care.
Role of the Sponsor: The funding organization had no role in the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript.
Previous Presentation: An earlier version of this work was presented at the national meeting of the Society of General Internal Medicine; Minneapolis, Minnesota; April 30, 2010; and at the national meeting of Academy Health; Boston, Massachusetts; June 28, 2010.
Disclaimer: The study contents are solely the responsibility of the authors and do not necessarily represent the official views of the Department of Health and Human Services.
Additional Contributions: We thank Benjamin Sommers, MD, PhD, Harvard School of Public Health, for his editing assistance and helpful comments on the manuscript. He did not receive compensation for the contribution.