1. Departments of Medicine, Obstetrics and Gynecology, and Epidemiology, University of Michigan, Ann Arbor, MI
2. Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN
3. Department of Biostatistics, MD Anderson Cancer Center, Houston, TX
4. Department of Medicine, University of Michigan, Ann Arbor, MI
5. Division of Research, Kaiser Permanente Northern California, Oakland, CA
6. Department of Medicine, University of California, Davis, CA.