Received: 27 April 2018
Accepted: 15 January 2019
First Online: 26 February 2019
Ethics approval and consent to participate
: This study was approved by the medical ethical committee of the University Hospitals Leuven and the Katholieke Universiteit Leuven (ML5739), Leuven, Belgium, on 12 May of 2009 as S51642. All procedures performed are in accordance with the ethical standarts of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.
: An informed consent was obtained in written from all individual participants and their parents/caregivers included in the study prior to data collection.
: The authors declare that they have no competing interests.
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