1. Respiratory Effectiveness Group, Cambridge, UK
2. Pneumology Department, Hospital Arnau de Vilanova, Valencia, Spain
3. CIBER de Enfermedades Respiratorias (CIBERES), Spain
4. Respiratory Department, Hospital de Alta Resolucion de Loja, Loja, Spain
5. Centre of Academic Primary Care, University of Aberdeen, Aberdeen, UK
6. Pneumology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain