1. Respiratory Department, Hospital Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
2. Department of Biostatistics, Hospital Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
3. Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, Missouri
4. Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
5. Center for Outcomes Research and Evaluation (CORE), Yale University School of Medicine, New Haven, Connecticut
6. Cardiovascular Research Foundation, New York, New York
7. CIBER Enfermedades Respiratorias (CIBERES), Madrid, Spain
8. Department of Medicine, Universidad de Alcalá, Madrid, Spain