Author Contributions: Dr Wolk, principal investigator of the Swedish Mammography Cohort, 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: Wolk, Larsson, Johansson, Ekman.
Acquisition of data: Wolk.
Analysis and interpretation of data: Wolk, Larsson, Johansson, Ekman.
Drafting of the manuscript: Wolk.
Critical revision of the manuscript for important intellectual content: Wolk, Larsson, Johansson, Ekman.
Statistical analysis: Wolk, Larsson.
Obtained funding: Wolk.
Administrative, technical, or material support: Wolk.
Study supervision: Wolk, Johansson, Ekman.
Financial Disclosures: None reported.
Funding/Support: This study was supported by grants from the Swedish Cancer Foundation, the Swedish Research Council/Longitudinal Studies, and Västmanland County Research Fund Against Cancer.
Role of the Sponsors: The funding sources had no role in the design and conduct of the study, in the collection, management, analysis, or interpretation of the data, or in the preparation, review, or approval of the manuscript.