1. Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California
2. Kaiser Permanente Center for Health Research, Northwest/Hawaii, Portland, Oregon
3. Department of Medicine, University of California San Francisco, San Francisco, California
4. MedStar Research Institute, Washington, DC
5. Centers for Disease Control and Prevention, Atlanta, Georgia
6. Division of Epidemiology, University of Minnesota, Minneapolis, Minnesota
7. Section of General Internal Medicine, Minneapolis Veterans Affairs Medical Center, Minneapolis, Minnesota
8. Division of Clinical Epidemiology, University of Minnesota, Minneapolis, Minnesota
9. Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania