[1] IRCCS Burlo Garofolo, Inst Maternal & Child Hlth, Epidemiol & Biostat Unit, Trieste, Italy
[2] IRCCS Burlo Garofolo, Inst Maternal & Child Hlth, Dept Paediat, Trieste, Italy
[3] IRCCS Burlo Garofolo, Inst Maternal & Child Hlth, Res Direct, Trieste, Italy
[4] IRCCS Burlo Garofolo, Inst Maternal & Child Hlth, Unit Hlth Serv Res & Int Hlth, Trieste, Italy
[5] IRCCS Burlo Garofolo, Inst Maternal & Child Hlth, Dept Paediat Surg, Ear Nose & Throat Unit, Trieste, Italy