Funding for this research was provided by:
Śląski Uniwersytet Medyczny (KNW-1-170/N/7/K, KNW-1-096/K/6/K)
Text and Data Mining valid from 2018-08-13
Received: 3 November 2017
Accepted: 1 August 2018
First Online: 13 August 2018
Ethics approval and consent to participate
: This research project was accepted by the ethical board of the Medical University of Silesia in Katowice, Poland (KNW/0022/KBI/74/16). A written informed consent was obtained from caregivers of all the children and in case of participants older than 16 years also from the child.
: Not applicable.
: The authors declare that they have no competing interests.
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