1. Department of Speech Pathology, Good Shepherd Penn Partners, Philadelphia, Pennsylvania;
2. Department of Pulmonary Medicine, and
3. Department of Critical Care Medicine, Respiratory Institute, Cleveland Clinic, Cleveland, Ohio;
4. Center for Clinical Epidemiology and Biostatistics,
5. Division of Pulmonary, Allergy, and Critical Care Medicine, and
6. Glasgow Royal Infirmary, National Health Service Greater Glasgow and Clyde, Glasgow, Scotland; and
7. School of Medicine, Dentistry and Nursing, University of Glasgow, Glasgow, Scotland
8. Palliative and Advanced Illness Research Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania;