1. Perelman School of Medicine, University of Pennsylvania, Philadelphia2Leonard Davis Institute of Health Economics, The Wharton School, University of Pennsylvania, Philadelphia3Corporal Michael J. Cresencz VA Medical Center, Philadelphia, Pennsylvania
2. New York University School of Medicine, New York
3. Perelman School of Medicine, University of Pennsylvania, Philadelphia2Leonard Davis Institute of Health Economics, The Wharton School, University of Pennsylvania, Philadelphia
4. Perelman School of Medicine, University of Pennsylvania, Philadelphia