1. Service of Preventive Medicine, University Hospital Complex of Ourense, Ourense, Spain
2. Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela, Spain
3. Service of Neumology, University Hospital Complex of Vigo, Vigo, Spain
4. Service of Preventive Medicine, University Hospital Lucus Augusti, Lugo, Spain
5. Service of Oncology, University Hospital Puerta de Hierro, Madrid, Spain
6. 5CIBER de Epidemiología y Salud Pública CIBERESP, Santiago de Compostela, Spain
7. Service of Preventive Medicine, University Hospital Complex of Santiago de Compostela, Spain