1. San Pedro de Alcantara Hospital, Caceres, Spain
2. CIBER de enfermedades respiratorias (CIBERES), Madrid, Spain
3. Bio-Araba Research Institute, Vitoria-Gasteiz, Spain; Alava University Hospital
4. Department of Medicine of Basque Country University, Spain
5. Virgen del Rocio Hospital, Sevilla, Spain
6. Valdecilla Hospital, Santander, Spain
7. Germans Trials i Pujos Hospital, Barcelona, Spain
8. La Paz Hospital, IdiPAZ, Madrid, Spain
9. Sabadell Hospital, Corporació Sanitària Parc Taulí, Institut Universitari Parc Tauli-UAB, Sabadell, Spain
10. Sta Creu i Sant Pau Hospital, Barcelona, Spain
11. IIS-Fundación Jimenez Diaz, Madrid, Spain
12. Son Espases Universitary Hospital, Palma de Mallorca, Spain
13. IRB Lleida, Lleida, Spain
14. Clinic Hospital, Barcelona, Spain
15. Centro de Medicina Respiratoria, Paraná, Argentina
16. Clínica Angloamericana, Lima, Perú
17. Sleep Unit, Respiratory Department, Álava University Hospital, Álava, Spain
18. Infanta Sofía Hospital, San Sebastián de los Reyes, Madrid, Spain
19. Infanta Leonor Hospital, Madrid, Spain