1. Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore
2. Department of Hospital Epidemiology, Veterans Affairs Maryland Health Care System, Baltimore
3. Robert Wood Johnson Foundation Clinical Scholars Program, Yale University School of Medicine, New Haven, Connecticut
4. Department of Veterans Affairs West Haven, West Haven, Connecticut
5. Department of Pediatrics, University of Utah School of Medicine, Salt Lake City
6. Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
7. Department of Medicine and Center for Health Policy and Outcomes, Memorial Sloan Kettering Cancer Center, New York, New York