Author Contributions: Dr Chang 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: Chang, Stukel, Flood, Goodman.
Acquisition of data: Goodman.
Analysis and interpretation of data: Chang, Stukel, Flood, Goodman.
Drafting of the manuscript: Chang, Goodman.
Critical revision of the manuscript for important intellectual content: Chang, Stukel, Flood, Goodman.
Statistical analysis: Chang, Stukel, Goodman.
Obtained funding: Goodman.
Administrative, technical, or material support: Goodman.
Study supervision: Flood.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Goodman reported speaking fees from Texas Medical Association; Health Action Council, Cincinnati; Richard Stockton College of New Jersey; Iowa Health Business Alliance; Alliance for Academic Internal Medicine; American Medical Association; Connecticut Children's Hospital; Mt Sinai Hospital, New York; World Congress; Rutgers University; Baystate Medical Center; Brigham and Women's Hospital; ESRI Inc; Illinois Hospital Association; National Hospice Workgroup; National Association of Health Data Organizations; St. Peters University Hospital, New Brunswick, New Jersey; Massachusetts Hospital Association; Cooper Health System, Camden, New Jersey; Organizzato dal Laboratorio Management e Sanità Scuola Superiore Sant'Anna di Pisa; Kentucky Academy of Family Physicians; Southern Illinois University Health Policy Institute; Ohio University College of Osteopathic Medicine; Institute for Clinical Quality and Value; The Marwood Group; American Society of Clinical Oncologists; OR Manager; Delta Health Alliance; SUNY Upstate University; and Intermountain Healthcare; and consulting fees from Vermont Department of Banking, Insurance, Securities and Health Care Administration; HealthDialog; Colorado Foundation for Medical Care; Seyferth Blumenthal and Harris; and American Medical Forensic Specialists. Drs Chang, Stukel, and Flood reported no disclosures.
Funding/Support: This research was supported in part by the Robert Wood Johnson Foundation and grant P01 AG19783 from the National Institute on Aging.
Role of the Sponsors: The Robert Wood Johnson Foundation and the National Institute on Aging had no role in the design and conduct of the study, in the collection, management, analysis, and interpretation of the data, or in the preparation, review, or approval of the manuscript.
This article was corrected for errors on June 7, 2011.