1. Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela, La Coruña - Spain
2. Pulmonary Department, Hospital Álvaro Cunqueiro, EOXI Vigo, NeumoVigoI+I Research Group, Vigo Biomedical Research Institute (IBIV), Vigo - Spain
3. CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid - Spain
4. Service of Preventive Medicine, University Hospital, Complex of Santiago de Compostela, Santiago de Compostela, La Coruña - Spain