1. Department of MedicineJohns Hopkins Hospital and Johns Hopkins School of Medicine Baltimore Maryland USA
2. Division of Health Care Policy and ResearchRobert D. and Patricia E. Kern Center for the Science of Health Care DeliveryMayo Clinic Rochester Minnesota USA
3. Department of MedicineSection of General Internal MedicineYale University School of Medicine New Haven Connecticut USA
4. Department of Health Policy and ManagementYale University School of Public Health New Haven Connecticut USA
5. Center for Outcomes Research and EvaluationYale–New Haven Hospital New Haven Connecticut USA