Document is current

Article History

Received: 4 November 2017

Accepted: 31 August 2018

First Online: 15 September 2018

Ethics approval and consent to participate

: The study was reviewed and approved by the Bioethics Commission of the Medical Faculty at University of Rzeszow (5/2/2017). Written informed consent was obtained from all the parents or legal guardians of the children, after being informed of the study objectives. Participants aged 16 or more signed an informed consent form as well.

: Not applicable.

: The authors declare that they have no competing interests.

: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.