Author Contributions: Dr Carnethon 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: Carnethon, Gulati.
Analysis and interpretation of data: Carnethon, Gulati, Greenland.
Drafting of the manuscript: Carnethon.
Critical revision of the manuscript for important intellectual content: Gulati, Greenland.
Statistical analysis: Carnethon, Gulati.
Obtained Funding: Carnethon, Greenland.
Financial Disclosures: None reported.
Funding/Support: Financial support for data collection was provided by the National Center for Health Statistics (NCHS), a part of the Centers for Disease Control and Prevention, Department of Health and Human Services. Dr Carnethon was supported in part by a career development award from the National Heart, Lung, and Blood Institute, National Institutes of Health (5 K01 HL73249-02).
Role of the Sponsor: All data used in this study were collected by the NCHS; the NCHS had no role in the design and conduct of the study; the analysis and interpretation of the data; or the preparation, review, or approval of the manuscript.