ИСТИНА

Introduction The Nijmegen questionnaire (Van Dixhoorn, Duivenvoordent, 1985) was developed in the 1980s to assess the severity of hyperventilation syndrome, which causes respiratory alkalosis and, as a result, polysystemic functional symptoms. Later, this questionnaire was recommended for use in the diagnosis of dysfunctional breathing. The COVID-19 pandemic provokes anxiety as a stressful event and objectifies the respiratory function, which becomes a favorable ground for the growth of the prevalence of dysfunctional breathing in society. Objectives To validate the Naimigen questionnaire in the context of the COVID-19 pandemic among the Russian-speaking population. Methods The author's socio-demographic questionnaire and the Nijmegen Questionnaire (NQ) were used (Van Dixhoorn, Duivenvoordent, 1985). The study was conducted online from April 27 to December 28, 2020. It was attended by 1,362 people from all regions of Russia, including 1,153 women and 209 men aged 15 to 88 years (38.3 ±11.4). Results The stable reliability of the Alpha-Kronbach coefficients (> 0.877) was revealed for all NQ points. To check the factor structure of the Naimigen questionnaire, we conducted an exploratory factor analysis using the direct Oblimin criterion, which, when explaining 57.3% of the total variance, allowed us to identify 4 factors: respiratory symptoms, paresthesia and gastrointestinal symptoms, tension, derealization. The average score in a healthy sample during the COVID-19 pandemic is 17.57±10.02. Initially, the threshold score for confirming dysfunctional breathing was at the level of 23 points (Thomas et al., 2001). If we rely on it, then among all respondents, signs of DB during the pandemic are found in 377 people, i.e. 27.7% of the entire sample. Conclusions. Checking the reliability and factor structure of the Naimigen questionnaire allows us to reasonably use this questionnaire on a Russian-language sample. The high prevalence of dysfunctional breathing revealed by the Naimigen questionnaire justifies the relevance of the study of this phenomenon and its predictors in the conditions of the COVID-19 pandemic. Disclosure: Research is supported by the Russian Science Foundation, project No. 21-18-00624.