1. Lieutenant Colonel Charles S. Kettles VA Medical Center Center for Clinical Management Research Ann Arbor MI USA
2. Department of Sociology Population Studies Center University of Michigan Ann Arbor MI USA
3. Division of Pulmonary and Critical Care Medicine Department of Internal Medicine University of Michigan Ann Arbor MI USA
4. Division of Pulmonary and Critical Care Medicine The Johns Hopkins University School of Medicine Baltimore MD USA
5. Center for Healthcare Outcomes and Policy University of Michigan Ann Arbor MI USA
6. Department of Internal Medicine University of Michigan Ann Arbor MI USA
7. Health Policy and Management, School of Public Health The Johns Hopkins University Baltimore MD USA