Author Contributions: Dr Eliassen 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: Eliassen, Colditz, Willett, Hankinson.
Acquisition of data: Colditz, Willett, Hankinson.
Analysis and interpretation of data: Eliassen, Colditz, Rosner, Willett, Hankinson.
Drafting of the manuscript: Eliassen.
Critical revision of the manuscript for important intellectual content: Eliassen, Colditz, Rosner, Willett, Hankinson.
Statistical analysis: Eliassen, Rosner.
Obtained funding: Colditz, Hankinson.
Administrative, technical, or material support: Colditz, Willett, Hankinson.
Study supervision: Colditz, Hankinson.
Financial Disclosures: None reported.
Funding/Support: This study was supported by research grant CA87969 from the National Cancer Institute. Dr Eliassen was supported by training grant DAMD17-00-1-0165 from the Department of Defense and Cancer Education and Career Development grant R25 CA098566-02 from the National Cancer Institute. Dr Colditz was supported in part by a Cissy Hornug Clinical Research Professorship from the American Cancer Society.
Role of the Sponsor: The funding organizations had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.
Acknowledgment: We gratefully acknowledge the Nurses' Health Study participants for their continuing cooperation.