1. Division of General Internal Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
2. Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
3. Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA, USA
4. Department of Emergency Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
5. Department of Medical Ethics and Health Policy, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA