Author Contributions: Dr Curtis 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: Curtis, Al-Khatib, Hernandez.
Acquisition of data: Curtis, Shea.
Analysis and interpretation of data: Curtis, Al-Khatib, Shea, Hammill, Hernandez, Schulman.
Drafting of the manuscript: Curtis.
Critical revision of the manuscript for important intellectual content: Curtis, Al-Khatib, Shea, Hammill, Hernandez, Schulman.
Statistical analysis: Curtis, Shea, Hammill.
Obtained funding: Curtis.
Administrative, technical, or material support: Shea, Schulman.
Study supervision: Al-Khatib, Schulman.
Financial Disclosures: Dr Curtis reported receiving research and salary support from Allergan Pharmaceuticals, GlaxoSmithKline, Lilly, Medtronic, Novartis, Ortho Biotech, OSI Eyetech, Pfizer, and Sanofi-Aventis. Dr Curtis has made available online a detailed listing of financial disclosures (http://www.dcri.duke.edu/research/coi.jsp). Dr Al-Khatib reported receiving research support and honoraria for presentations from Medtronic. Dr Hernandez reported receiving research grants from GlaxoSmithKline, Medtronic, Roche Diagnostics, and Scios and serving on the speaker's bureau or receiving honoraria in the past 5 years from Novartis. Dr Schulman reported receiving research and salary support from Actelion Pharmaceuticals, Allergan Pharmaceuticals, Amgen, Bristol-Myers Squibb, Ernst & Young, Genentech, GlaxoSmithKline, IBM Center for Healthcare Management, Inspire Pharmaceuticals, Johnson & Johnson, Kureha Corporation, Lilly Foundation, Medtronic, NABI Biopharmaceuticals, Novartis, OSI Eyetech, Pfizer, Pharmacia, Purdue Pharma, Sanofi-Aventis, Scios, Theravance, Wyeth, and Yamanouchi USA Foundation; receiving personal income for consulting from Genentech, The Health Strategies Consultancy, and the National Pharmaceutical Council; having equity in and serving on the board of directors of Cancer Consultants; having equity in and serving on the executive board of Faculty Connection LLC; and having equity in Alnylam Pharmaceuticals. Dr Schulman has made available online a detailed listing of financial disclosures (http://www.dcri.duke.edu/research/coi.jsp). Ms Shea and Mr Hammill did not report any disclosures.
Funding/Support: This study was funded by grant 1R01AG026038-01A1 from the National Institute on Aging and grant 5U01HL66461-05 from the National Heart, Lung, and Blood Institute.
Role of the Sponsors: The National Institute on Aging and the National Heart, Lung, and Blood Institute had no role in the design and conduct of the study; the collection, analysis, and interpretation of the data; or the preparation, review, or approval of the manuscript.
Additional Contributions: We thank Damon M. Seils, MA, of Duke University for editorial assistance and manuscript preparation. Mr Seils received no compensation for his assistance apart from his employment at the institution where the study was conducted.