1. Departments of Health Policy and Management, The Johns Hopkins University, Baltimore, Maryland.
2. Department of Epidemiology, Divisions of Pulmonary and Critical Care Medicine, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland.
3. Merck & Co., Inc., West Point, Pennsylvania.
4. Internal Medicine, Department of Medicine, School of Medicine, The Johns Hopkins University, Baltimore, Maryland.
5. Department of Health Policy and Management, and Epidemiology, Bloomberg School of Public Health, Internal Medicine, Department of Medicine, School of Medicine, The Johns Hopkins University, Baltimore, Maryland.