1. Center for Surgery and Health Economics, Department of Surgery, University of Pennsylvania, Philadelphia
2. Perelman School of Medicine, University of Pennsylvania, Philadelphia
3. Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia
4. Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia
5. Department of Family Medicine and Community Health, Perelman School of Medicine, University of Pennsylvania, Philadelphia
6. Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia
7. Department of Emergency Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia