1. Office of Health Policy and Clinical Outcomes, Thomas Jefferson University, Philadelphia, Pennsylvania
2. Center for Pharmaceutical Appraisal and Outcomes Research, Abbott Laboratories, Abbott Park, Illinois
3. Division of Gastroenterology, Thomas Jefferson University, Philadelphia, Pennsylvania
4. New York, New York
5. Office of Health Policy and Clinical Outcomes, Thomas Jefferson University, Philadelphia, Pennsylvania; Dr. Raymond C. and Doris N. Grandon, Professor of Health Policy, Thomas Jefferson University, Philadelphia, Pennsylvania