1. Division of Pulmonary and Critical Care, Department of Medicine, Harborview Medical Center, University of Washington, Seattle WA, USA
2. Division of Medical Oncology, Department of Medicine, Seattle Cancer Care Alliance, University of Washington and Fred Hutchinson Cancer Research Center, Seattle WA, USA
3. Division of Pulmonary and Critical Care, Department of Medicine, Medical University of South Carolina, Charleston, SC, USA
4. School of Nursing, Oregon Health & Sciences University, Portland, OR, USA