Author contribution: Kozelsky AS — data acquisition and analysis, manuscript writing; Kaminer DD — study concept, manuscript writing; Zharov AR — manuscript writing and editing; Korolik VV — literature review, acquisition and analysis of literary sources, analysis of regulations and procedures; all authors confirm that their authorship is compliant with international ICMJE criteria (all authors contributed significantly to the development of the concept, conduct of the study and preparation of the article, read and approved the final version before publishing).