1. Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California
2. Division of General Medical Disciplines, Stanford University School of Medicine, Stanford, California
3. Quantitative Sciences Unit, Stanford University School of Medicine, Stanford, California
4. Department of Community Health and Social Sciences, Graduate School of Public Health and Health Policy, City University of New York, New York, New York
5. Department of Medicine, University of California, San Francisco, School of Medicine