1. Pulmonary, Allergy and Critical Care Division, Department of Medicine
2. Palliative and Advanced Illness Research Center, Department of Medicine
3. General Internal Medicine, Department of Medicine, and
4. Philadelphia Veterans Administration (VA) Medical Center, Philadelphia, Pennsylvania
5. Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
6. Pulmonary and Critical Care Division, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan; and
7. VA Center for Clinical Management Research, VA Ann Arbor Health System, Ann Arbor, Michigan
8. Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania