Published Online: April 2, 2012. doi:10.1001/archinternmed.2012.198
Author Contributions:Study concept and design: Tsai, Grant, and Atrash. Acquisition of data: Tsai. Analysis and interpretation of data: Tsai, Grosse, Hooper, and Atrash. Drafting of the manuscript: Tsai and Atrash. Critical revision of the manuscript for important intellectual content: Tsai, Grosse, Grant, Hooper, and Atrash. Statistical analysis: Tsai and Grosse. Administrative, technical, and material support: Grant. Study supervision: Grant and Atrash.
Financial Disclosure: None reported.
Disclaimer: The findings and conclusions in this Research Letter are those of the authors and do not necessarily represent the views of the Research Data Center, the National Center for Health Statistics, or the Centers for Disease Control and Prevention.
Additional Contributions: Stephanie Robinson, MPH, of the Research Data Center, National Center for Health Statistics, Centers for Disease Control and Prevention, coordinated the review of our research proposal and provided administrative and technical support for accessing the data.