1. Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain
2. CIBER de Epidemiología y Salud Pública, CIBERESP, Spain
3. Department of Oncology, Puerta de Hierro University Hospital, Majadahonda, Madrid, Spain
4. Health Research Institute Puerta de Hierro, Majadahonda, Madrid, Spain