1. Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia
2. Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia
3. Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania
4. Department of Epidemiology, Johns Hopkins University, Baltimore, Maryland
5. Department of Medicine, Yale–New Haven Hospital, New Haven, Connecticut
6. Department of Emergency Medicine, University of Pennsylvania, Philadelphia
7. Department of Medicine, Johns Hopkins University, Baltimore, Maryland