1. Department of Medicine, Section of Pulmonary and Critical Care Medicine, The University of Chicago, Chicago, Illinois
2. Department of Pulmonary Medicine, Koc University School of Medicine, Istanbul, Turkey
3. Department of Clinical Sciences, Respiratory Medicine and Allergology, Faculty of Medicine, Lund University, Lund, Sweden; and
4. Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania