1. Department of Biostatistics and Epidemiology, University of Massachusetts Amherst, Amherst, Massachusetts
2. Massachusetts Department of Public Health, Office of Elder Health, Boston, Massachusetts
3. Department of Health and Social Behavior, Harvard School of Public Health, Boston, Massachusetts
4. Department of Health and Social Behavior, Harvard School of Public Health, Boston, Massachusetts; Dana-Farber Cancer Institute, Center for Community Based Research, Boston, Massachusetts
5. Centers for Disease Control and Prevention, Division of Nutrition and Physical Activity, Atlanta, Georgia