1. Department of Medical Ethics and Health Policy, Perelman School of Medicine University of Pennsylvania Philadelphia Pennsylvania USA
2. Center for Health Systems Research Sutter Health Walnut Creek California USA
3. Leonard Davis Institute of Health Economics University of Pennsylvania Philadelphia Pennsylvania USA
4. Corporal Michael J. Crescenz VA Medical Center Philadelphia Pennsylvania USA
5. Department of Medicine University of Washington School of Medicine Seattle Washington USA
6. Ascension St. Louis Missouri USA
7. Department of Emergency Medicine and Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine University of Pennsylvania Philadelphia Pennsylvania USA