1. Department of Nutrition, Harvard School of Public Health, Channing Laboratory, Boston, Massachusetts
2. Department of Health and Social Behavior, Harvard School of Public Health, Channing Laboratory, Boston, Massachusetts
3. Department of Epidemiology, Harvard School of Public Health, Channing Laboratory, Boston, Massachusetts
4. Beth Israel Deaconess Medical Center, Boston, Massachusetts
5. Department of Medicine, Brigham and Woman’s Hospital and Harvard Medical School, Boston, Massachusetts
6. Sexual Health Team, Pfizer, Inc, New York, New York