Author Contributions: Drs Djoussé and Gaziano had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Djoussé, Driver.
Acquisition of data: Gaziano.
Analysis and interpretation of data: Djoussé, Driver.
Drafting of the manuscript: Djoussé.
Critical revision of the manuscript for important intellectual content: Djoussé, Driver, Gaziano.
Statistical analysis: Djoussé, Driver.
Obtained funding: Gaziano.
Administrative, technical, or material support: Djoussé, Gaziano.
Study supervision: Gaziano.
Financial Disclosures: Dr Djoussé reported that he is currently the recipient of investigator-initiated grants from the National Institutes of Health and that over the past 5 years he has received investigator-initiated grants from the Huntington's Disease Society of America, the National Institutes of Health, and the Biomedical Research Institute, Brigham and Women's Hospital. Dr Driver reported receiving research grants from the Parkinson's Disease Foundation, the Hartford Foundation's Center of Excellence in Geriatric Medicine at Harvard Medical School, and the Eleanor and Miles Shore/Harvard Medical School Scholars in Medicine Program and that she is currently the recipient of a Career Development Award from the Department of Veterans Affairs. Dr Gaziano reported that over the past 5 years he has received investigator-initiated research grants from the Department of Veterans Affairs, National Institutes of Health, Veroscience, and Amgen; has served as a consultant for and has received honoraria from Bayer; and has served as an expert witness for Merck.
Funding/Support: The Physicians' Health Study (PHS) is supported by grants CA-34944, CA-40360, and CA-097193 from the National Cancer Institute and grants HL-26490 and HL-34595 from the National Heart, Lung, and Blood Institute, Bethesda, Maryland.
Role of the Sponsors: The National Cancer Institute and the National Heart, Lung, and Blood Institute had no role in the design and conduct of the study; the collection, management, analysis, and interpretation of the data; or the preparation, review, or approval of the manuscript.
Disclaimer: Dr Gaziano, a contributing editor for JAMA, was not involved in the editorial review of or the decision to publish this article.
Additional Contributions: We thank the participants in the PHS for their outstanding commitment and cooperation and the entire PHS staff for their expert and unfailing assistance.