Text and Data Mining valid from 2020-05-06
Received: 31 March 2020
Accepted: 22 April 2020
First Online: 6 May 2020
Ethics approval and consent to participate
: The study was performed in accordance with the Declaration of Helsinki and approved by the relevant local ethics committee (reference 12-5120-BO). The parents and/or legal guardians provided informed consent.
: Not applicable.
: The authors declare that they have no competing interests.