1. Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill
2. Medical student, University of North Carolina School of Medicine, Chapel Hill
3. Division of Hospitalist Medicine, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill
4. Division of Neuromuscular Diseases, Department of Neurology, Duke University School of Medicine, Durham, North Carolina
5. Department of Epidemiology, University of North Carolina School of Public Health, Chapel Hill
6. Center for Aging and Health, Division of Geriatric Medicine, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill