Received: 19 July 2018
Accepted: 21 May 2019
First Online: 27 May 2019
Ethics approval and consent to participate
: Informed written consent was obtained from all individual participants included in the study. All procedures in the study that involved human participants were performed in accordance with the ethical standards of the institutional and the national research committee, and in conformance with the 1964 Helsinki declaration with later amendments or comparable ethical standards. The Bioethical Committee of the Wrocław Medical University, Poland approved the study, decision number: 557/2014.
: Not applicable.
: The authors declare that they have no competing interests.