Author contributions: Gruzdeva АА, Khokhlov АL, Ilyin МV — trial concept and design; Gruzdeva АА, Ilyin МV, Mushnikov DL– data capture and processing, Gruzdeva АА, Ilyin МV, Mushnikov DL — analysis and interpretation of results; Gruzdeva АА, Mushnikov DL — writing an article; Khokhlov АL, Ilyin МV — preparation and approval of a manuscript for publication.

Compliance with ethical standards: the study was approved by the Ethical Committee of the Yaroslavl State Medical University of the Ministry of Health of the Russian Federation (protocol No. 21 as of February 08, 2018). The informed voluntary consent was obtained for every participant. Adults were interviewed on a voluntary basis using questionnaires. The conducted trial doesn’t expose participants to danger and corresponds to the requirements of biomedical ethics.