[1] Univ Palermo, Sect Gastroenterol & Hepatol Internal Med & Med S, Dept Hlth Promot Sci Maternal & Infant Care, I-90127 Palermo, Italy
[2] Univ Palermo, Dept Surg Oncol & Oral Sci DiChirOnS, I-90127 Palermo, Italy
[3] Univ Palermo, PROMISE, Dept Hlth Promot Sci Maternal & Infant Care Inter, I-90127 Palermo, Italy
[4] Univ Palermo, Dipartimento Sci Econ Aziendali & Stat, I-90133 Palermo, Italy
[5] IRCCS Osped Policlin San Martino, UO Epidemiol Clin, I-16132 Genoa, Italy