Affiliation: | a Section of Obstetrics and Gynecology, PanHellenic Association for Continual Medical Research, Athens, Greece b Section of Dentistry and Oral Health, PanHellenic Association for Continual Medical Research, Athens, Greece c Section of Public Health, PanHellenic Association for Continual Medical Research, Athens, Greece d Instituto di Statistica Medica e Biometria, University of Milan, Milan, Italy |