Funding for this research was provided by:
Lietuvos Mokslo Taryba (MIP-003/2013)
Received: 12 March 2019
Accepted: 12 July 2019
First Online: 23 July 2019
Ethics approval and consent to participate
: Parental or guardian consent was sought prior to data collection. Written parental consent was obtained on behalf of all study participants below the age of 18. Participants aged 18 and above provided written informed consent. The study was approved by Kaunas Regional Bioethics Committee (2012-12-14; Reference number BE-2-45) and Lithuanian Ministry of Education and Science.
: Not applicable.
: The authors declare that they have no competing interests.