1. Pharmacology, Kaiser Permanente Northern California, California, USA;
2. Gastroenterology, Kaiser Permanente Northern California, California, USA;
3. Department of Medicine, University of Texas Southwestern Medical Center, Texas, USA;
4. Hospital Based Service, Kaiser Permanente Northern California, California, USA;
5. Gastroenterology, Kaiser Permanente Northern California, University of California at San Francisco, California, USA.