1 Division of Allergy, Pulmonary, and Critical Care Medicine, Nashville, TN; Center for Health Services Research, Nashville, TN; Geriatric Research, Education and Clinical Center Service, Department of Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN. Electronic address: wes.ely@vanderbilt.edu.
2 Center for Health Services Research, Nashville, TN; Division of General Internal Medicine and Public Health, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN; Geriatric Research, Education and Clinical Center Service, Department of Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN.
3 Division of Allergy, Pulmonary, and Critical Care Medicine, Nashville, TN; Center for Health Services Research, Nashville, TN.