1. Kaiser Permanente Research, Kaiser Permanente, Pasadena, California
2. Kaiser Permanente Center for Effectiveness and Safety Research, Kaiser Permanente, Pasadena, California
3. Department of Internal Medicine, Transplant Hepatology, Southern California Permanente Medical Group, Los Angeles
4. Division of Research, Kaiser Permanente Northern California, Oakland
5. Department of Health Outcomes & Biomedical Informatics, University of Florida College of Medicine, Gainesville
6. Department of Medicine, University of Florida College of Medicine, Gainesville