[1] Natl Res Council Italy, Inst Res & Biomed Innovat, IRIB, Via Ugo La Malfa 153, I-90146 Palermo, Italy
[2] Univ Palermo, Dept Hlth Promot Mother & Child Care, Internal Med & Med Special, Palermo, Italy
[3] Univ Naples Federico II, Dept Translat Med Sci, Via Sergio Pansini 5, I-80131 Naples, Italy
[4] Acad Dept Pediat Hosp Bambino Gesu, Pediat Pulmonol & Sleep & Long Term Ventilat Unit, Piazza S Onofrio 4, I-00165 Rome, Italy
[5] Univ Padua, Dept Womens & Childrens Hlth, Div Emergency Med, Padua, Italy
[6] Univ Bologna, Dept Med & Surg Sci, Pediat Unit, I-40138 Bologna, Italy
[7] Univ Pavia, Fdn IRCCS Policlin San Matteo, Pediat Clin, Piazzale Golgi 19, I-27100 Pavia, Italy
[8] Sapienza Univ Rome, Dept Paediat, Rome, Italy
[9] IRCCS, Azienda USL, Dept Obstet Gynecol & Pediat, Pediat Unit, Viale Risorgimento 80, I-42123 Reggio Emilia, Italy
[10] Univ Milan, Dept Pediat, Osped Bambini, Milan, Italy
[11] Anna Meyer Childrens Univ Hosp, Unit Epidemiol, Viale Pieraccini 24, I-50139 Florence, Italy