1. Istituto di Ricerche Farmacologiche Mario Negri IRCCS; Laboratory Methodology for Clinical Research; Via La Masa, 19 Milan Italy
2. Cardinal Massaia Hospital; Pediatric Unit; Corso Dante Alighieri 202 Asti Asti Italy 14100
3. University of Turin; Department of Public and Pediatric Health Sciences; Piazza Polonia 94 Turin Turin Italy 10126
4. University of Milan; Department of Biomedical Sciences for Health; Via Pascal 36 Milan Italy 20133
5. IRCCS Galeazzi Orthopaedic Institute; Clinical Epidemiology Unit; Milan Italy
6. Regina Margherita Children's Hospital; Department of Pediatrics; Città del Salute e della Scienza di Torino Piazza Polonia, 94 Torino Italy 10126