1. Pulmonary Service and Research Institute Doce de Octubre University Hospital Madrid Spain
2. CIBER Enfermedades Respiratorias (CIBERES) Madrid Spain
3. Instituto de Biomedicina de Sevilla (IBiS) Hospital Universitario Virgen del Rocío/Universidad de Sevilla Sevilla Spain
4. Department of Economics Universitat Jaume I Castellón Spain
5. Department of Statistics and Operational Research University of Valencia Valencia Spain
6. Thorax Institute Hospital Clinic IDIBAPS Universitat de Barcelona and CIBER Enfermedades Respiratorias FISIB Mallorca Spain
7. Unidad de Bioestadística Clínica Ramón y Cajal University Hospital IRYCIS Madrid Spain
8. Centre for Biomedical Research on Epidemiology and Public Health (CIBERESP) Instituto de Salud Carlos III Madrid Spain