Author Contributions: Drs Kenfield and Colditz had full access to all of the data in the study and take responsibility for the integrity of the data and accuracy of the data analysis.
Study concept and design: Kenfield, Stampfer, Rosner, Colditz.
Acquisition of data: Kenfield, Stampfer, Colditz.
Analysis and interpretation of data: Kenfield, Stampfer, Rosner, Colditz.
Drafting of the manuscript: Kenfield.
Critical revision of the manuscript for important intellectual content: Kenfield, Stampfer, Rosner, Colditz.
Statistical analysis: Kenfield, Rosner.
Obtained funding: Stampfer, Colditz.
Administrative, technical, or material support: Colditz.
Study supervision: Stampfer, Colditz.
Financial Disclosures: None reported.
Funding/Support: The project was supported by grants R25CA098566 and T32CA09001 from the National Institutes of Health, the Association of Schools of Public Health, and the Legacy Foundation.
Role of the Sponsor: The funding sources had no role in the design or conduct of the study; the collection, management, analysis, and interpretation of the data; or the preparation, review, or approval or the manuscript.
Disclaimer: The content of this article is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute of the National Institutes of Health, the Association of Schools of Public Health, the Legacy Foundation, the Legacy Foundation staff, or the Legacy Foundation's Board of Directors.
Additional Contributions: We thank the participants and staff of the Nurses' Health Study for their valuable contributions. Special thanks to Weiliang Qiu, PhD (Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts) for his graphical expertise. Dr Qiu was not compensated for his contribution.