Study concept and design: Shiroma, Freedson, Lee.
Acquisition of data: Shiroma, Lee.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: Shiroma, Trost, Lee.
Critical revision of the manuscript for important intellectual content: Freedson, Lee.
Statistical analysis: Shiroma, Lee.
Obtained funding: Lee.
Administrative, technical, or material support: All authors.
Study supervision: Lee.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Drs Freedson and Trost are members of the Actigraph scientific advisory board. No other disclosures were reported.
Funding/Support: This research was supported by research grants CA154647, CA047988, CA121005, HL099557, HL043851, HL080467, HL099355, and HL007575 from the National Institutes of Health.
Role of the Sponsor: The National Institutes of Health had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Contributions: We are grateful to the staff of the Women’s Health Study (Brigham and Women’s Hospital), particularly Ara Sarkissian, MM, Bonnie Church, BA, Colby Smith, and Jane Jones, MEd. None of the persons named were compensated.