1. Department of Respiratory Medicine, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain
2. CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
3. Department of Respiratory Medicine, Hospital Arquitecto Marcide, Ferrol, Spain
4. Department of Respiratory Medicine, Hospital Lucus Augusti, C/ Dr Ulises Romero, nº 1, Lugo, 27004, Spain