1. Department of Respiratory, Hospital Ramón y Cajal (IRYCIS), Madrid, Spain
2. Department of Medicine, Universidad de Alcalá (IRYCIS), Madrid, Spain
3. Division of Cardiology, Department of Medicine, Columbia University Medical Center, New York-Presbyterian Hospital, New York, New York, United States
4. Center for Outcomes Research and Evaluation (CORE), Yale University School of Medicine, New Haven, Connecticut, United States
5. Department of Internal Medicine, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
6. Universidad Católica de Murcia, Murcia, Spain
7. Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, Missouri, United States
8. Division of General Medical Sciences, Washington University School of Medicine, St. Louis, Missouri, United States