1. Preventive Medicine and Public Health, Rey Juan Carlos University, 28922 Madrid, Spain
2. María Zambrano Program, European Union, Spain
3. Department of Preventive Medicine, Hospital Universitario Fundación Alcorcón, Rey Juan Carlos University, 28922 Madrid, Spain
4. CIBER of Respiratory Diseases (CIBERES), Instituto de Salud Carlos III, 28029 Madrid, Spain