1. 1 National Centre of Epidemiology, Instituto de Salud Carlos III, Madrid, Spain
2. 2 Division of Environmental and Reproductive Epidemiology, Biomedical Research Network on Epidemiology and Public Health (CIBERESP), Spain
3. 3 Department of Health Sciences. Universidad Rey Juan Carlos I, Madrid, Spain
4. 4 National School of Public Health, Instituto de Salud Carlos III, Madrid, Spain
5. 5 European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden