1. Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA;
2. Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA, USA;
3. Department of Population Health, Division of Health Care Delivery Science, NYU School of Medicine, New York, USA (Wharton School, University of Pennsylvania, Philadelphia, PA at the time of the study);
4. School of Social Policy and Practice, University of Pennsylvania, Philadelphia, PA, USA