Author Contributions: Dr Ness 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, acquisition of data, analysis and interpretation of data, drafting of the manuscript, critical revision of the manuscript for important intellectual content, and statistical analysis: Ness.
Financial Disclosures: None reported.
Funding/Support: This work was supported by contract IOM-2241-06-002 from the Institute of Medicine, National Academies.
Role of the Sponsor: The funding organization had input into the survey design and assisted in revision and approval of the manuscript.
Additional Contributions: Joint Policy Committee, Societies of Epidemiology leaders involved in the review of the manuscript include Mary Haan, DrPH, MPH, and Michael Bracken, PhD, MPH (Society for Epidemiologic Research); John Acquavella, PhD (American College of Epidemiology); George Rutherford, MD, and Ruth Etzel, MD (Section on Epidemiology, American Academy of Pediatrics); James A. Gaudino, MD, MPH, MS, Stanley H. Weiss, MD, and E. Oscar Alleyne, MPH (American Public Health Association Epidemiology Section); Dorothy Stephens, MPH, and Chandra Ford, PhD, MLIS (Society for the Analysis of African-American Public Health Issues); and Daniel Wartenberg, PhD (International Society for Environmental Epidemiology). We thank Joy Pritts, JD (Georgetown University), Roger Herdman, MD, and Harvey Fineberg, MD, PhD (Institute of Medicine) for their comments and suggestions on the manuscript. We also thank Debra Bass, MS, and Katherine Simpson for technical assistance. No one named herein received compensation for their contributions.