Text and Data Mining valid from 2020-03-18
Received: 10 September 2018
Accepted: 11 February 2020
First Online: 18 March 2020
Ethics approval and consent to participate
: The study was approved by the internal ethics committee of each participating School, in accordance with Italian law. In addition, all parents or legal guardians gave informed consent, and authorized researchers to use their data in accordance with Italian law. All procedures performed in the study were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Not applicable.
: The authors declare that they have no competing interests.