1. Department of Veterans Affairs, Puget Sound Health Care System, Health Services R&D, Seattle, Washington
2. School of Nursing, College of Behavioral, Social, and Health Sciences, Clemson University, Clemson, South Carolina
3. Department of Veterans Affairs, Portland Health Care System, Health Services R&D
4. Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science University, Portland, Oregon, USA