Author Contributions: Dr Gruen 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: Gruen, Campbell, Blumenthal.
Acquisition of data: Campbell, Blumenthal.
Analysis and interpretation of data: Gruen, Campbell, Blumenthal.
Drafting of the manuscript: Gruen, Campbell, Blumenthal.
Critical revision of the manuscript for important intellectual content: Gruen, Campbell, Blumenthal.
Statistical analysis: Gruen.
Obtained funding: Campbell, Blumenthal.
Administrative, technical, or material support: Campbell.
Study supervision: Campbell, Blumenthal.
Financial Disclosures: None reported.
Funding/Support: This research was funded by a grant from the Medicine as a Profession Project of the Open Society Institute. Dr Gruen reports being a 2002-2003 Harkness Fellow in Health Policy at the Harvard School of Public Health, receiving support from The Commonwealth Fund, and a being a Fellow in Medical Ethics at Harvard Medical School.
Role of the Sponsors: The sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; or preparation, review, or approval of the manuscript.
Acknowledgment: We thank Paul D. Cleary PhD, Yale School of Public Health, for advice on earlier drafts of the manuscript, Manju Ghokale, formerly of the Institute of Health Policy, Massachusetts General Hospital, Susan Regan PhD, Division of General Medicine, Massachusetts General Hospital and Harvard Medical School for assistance with data processing and analysis, and Janice Ballou and Frank Potter at Mathematica Policy Research Inc. Use of the US Burden of Disease and Injury Project data were provided by Catherine Michaud, MD, PhD, Center for Population and Development Studies, Harvard School of Public Health. The Social Capital Community Benchmark Survey data used in this study were collected by Robert D. Putnam of the Saguaro Seminar Civic Engagement in America, a project of the John F. Kennedy School of Government at Harvard University and numerous community foundations nationwide, and made available through the Roper Center for Public Opinion Research. None of the individuals listed in this acknowledgment received additional compensation for their work on this article.