VALIDATION OF THE EQ-5D-5L VERSION IN RUSSIA

The paper discusses the process for validation of the Russian-language EQ-5D-5L version to assess quality of life. According to international and national guidelines, the primary goal of treating spondyloarthritis (SpA) is to preserve the quality of life (QOL) of a patient as long as possible, by achieving control of the main symptoms of the disease and inflammation, by preventing the development and progression of structural changes in the locomotor system, and by preserving/normalizing the patient's functional activity and social adaptation. QOL is the integral characteristic of the physical, psychological, social and emotional status of the patient, which is assessed on the basis of his subjective perception. At the moment, there are no generally accepted national tools for assessing QOL in Russia, so the problem of adaptation and validation of international questionnaires is very actual. Objective : to evaluate the psychometric properties of the Russian-language EQ-5D-5L version in patients with SpA. Subjects and methods . Examinations were made in 163 patients older than 18 years with axial or peripheral SpA, who met the Assessment of Spondyloarthritis International Society (ASAS) criteria. The disease activity was assessed using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS); their functional status was estimated by the Bath Ankylosing Spondylitis Functional Index (BASFI), and spinal mobility was evaluated by the Bath Ankylosing Spondylitis Metrology Index (BASMI). The ASAS Health Index (HI) was used to comprehensively analyze the impact of SpA on the patient's health. The EQ-5D-5L version was employed for the first time in Russia to assess the quality of life of patients. Its main psychometric properties, such as reproducibility, validity, sensitivity, were evaluated. Results and discussion . The median age of the patients was 39.50 [28.00; 48.00] years. Among them, there were 64.8% of men. The median value of EQ-5D (a 5L version) was 0.53 [0.29; 0.65]. There were statistically significant relationships between the EQ-5D-5L values and BASDAI, BASFI, ASDAS, BASMI, ASAS HI, and the SF-36 questionnaire for QOL assessment. The test-retest reliability study showed that the internal consistency (Cronbach's alpha) was 0.96. The median value of the EQ-5D-5L was 0.55 [0.37; 0.63] at the first visit and 0.60 [0.40; 0.69] at the second visit after prescribing therapy (p = 0.01). Conclusion . The validation has indicated that the EQ-5D-5L version is a reliable, change-sensitive, easy-to-use, and physician-patient-friendly tool to assess QOL.