Received: 14 March 2019
Accepted: 27 August 2019
First Online: 6 September 2019
Compliance with ethical standards
: There is no conflict of interest. In this article, none of the authors have any relation, connection or monetary interest with regard to the subject or material mentioned in the study.
: All procedures performed in studies involving human participants 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. Informed child assent and written, informed parental consent to the research procedures and publication of results were obtained. Informed consent of the participants or their families was also collected.
: Informed consent was obtained from all individual participants included in the study.