1. Division of Pulmonary and Critical Care Medicine, Department of Medicine, Denver Health and Hospital Association, Denver, Colorado, USA.
2. Divisions of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.
3. Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado, USA.
4. Center for Bioethics and Humanities, University of Colorado School of Medicine, Aurora, Colorado, USA.
5. Department of Health System Management and Policy, University of Colorado Anschutz Medical Campus, Colorado School of Public Health, Aurora, Colorado, USA.
6. Department of Veteran Affairs Eastern Colorado Health Care System, Aurora, Colorado, USA.
7. Divisions of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.