1. Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC, Hyattsville, Maryland, USA
2. Division for Heart Disease and Stroke Prevention, National Center for Chronic Disease Prevention and Health Promotion, CDC, Atlanta, Georgia, USA
3. Division of Research and Methodology, National Center for Health Statistics, CDC, Hyattsville, Maryland, USA
4. Department of Medicine, Center for Behavioral Cardiovascular Health, Columbia University, Medical Center, New York, New York, USA
5. Department of Psychiatry and Behavioral Science, Applied Behavioral Medicine Research Institute, Stony Brook University, Stony Brook, New York, USA
6. Department of Epidemiology, University of Alabama at Birmingham, Birmingham, Alabama, USA