1. Division of Gastroenterology, University of Pennsylvania, Philadelphia
2. Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia
3. Center for Evidence-Based Practice, University of Pennsylvania Health System, Philadelphia
4. ECRI Evidence-based Practice Center, Center for Clinical Evidence and Guidelines, Plymouth Meeting, Pennsylvania
5. Division of General Internal Medicine, University of Pennsylvania, Philadelphia
6. Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia
7. Division of Neurology, Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania