REMEDIUMREMEDIUM1561-59362658-3534Joint-Stock Company Chicot158110.32687/1561-5936-2023-27-1-66-70Original ArticleInterpretation criteria for the Giessen Somatic Complaints Inventory based on the Rasch Metric SystemТomaschikТatyana Е.https://orcid.org/0000-0002-4819-759X, tantom2012@yandex.byLugovskayaAlena A.002Grodno State Medical University, Grodno, Belarus151220231667009102025Copyright © 2023,2023The Giessen Somatic Complaints Inventory is one of the popular questionnaires for assessing the clinical manifestations of somatoform disorders. The purpose of this study was to develop psychometrically sound criteria for assessing minimal clinically important difference in the condition of patients based on the modified Giessen Somatic Complaints Inventory. The Rasch metric system and the index of minimal detectable change for 95% probability were used to assess the psychometric properties of the Giessen Somatic Complaints Inventory and develop criteria minimal clinically important difference. Dynamic criteria for assessing minimal clinically important difference in the severity of somatic symptoms during repeated examinations for each total score on the scale were determined. Each summary score has its own statistical step, which reflects the minimal clinically important difference, and ranges from 6 to 23 points. The selected criteria are fully suitable for use in clinical practice and scientific research.somatoform disordersmethod for diagnosing somatoform disordersRasch metric systemindex of minimal detectable changeсоматоформные расстройстваметодика диагностики соматоформных расстройствметрическая система Рашаиндекс минимальных определяемых изменений1.International Classification of Diseases (10th revision). Classification of mental and behavioral disorders. St. Petersburg; 1994. 302 p. (In Russ.); 2. Guyatt G., Walter S., Norman G. Measuring change over time: assessing the usefulness of evaluative instruments. J. Clin. Epidemiol. 1987; 40(2): 171—178. doi: 10.1016/0021-9681(87)90069-5; 3. Jaeschke R., Singer J., Guyatt G. H. Measurement of health status. Control Clin. Trials. 1989; 10(4): 407—415. doi: 10.1016/0197-2456(89)90005-6; 4. Draaka T. H. P., de Greefa B. T. A., Fabera C. G., Merkiesa I. S. J. The minimum clinically important difference: which direction to take. Eur. J. Neurol. 2019; 26: 850—855. doi: 10.1111/ene.13941; 5. Assanovich M. A. Methodology and applied aspects of the Rasch metric system in clinical psychodiagnostics. Grodno; 2018. 428 p. (In Russ.); 6. Assanovich M. A. Methodological approaches to scientific measurement in clinical psychodiagnostics. Minsk; 2017. 224 p. (In Russ.); 7. Lin K. C., Hsieh Y. W., Wu C. Y. et al. Minimal detectable change and clinically important difference of the Wolf Motor Function Test in stroke patients. Neurorehabilitat. Neural Repair. 2009; 23(5): 429—434. doi: 10.1177/1545968308331144; 8. Wright A., Hannon J., Hegedus E. J., Kavchak A. E. Clinimetrics corner: a closer look at the minimal clinically important difference (MCID). J. Manual Manipulat. Ther. 2012; 20: 160—166. doi: 10.1179/2042618612Y.0000000001; 9. Assanovich M. V. Psychometric Characteristics and Diagnostic Criteria of the 5-Point Negative Symptoms Assessment (NSA-5) Scale for schizophrenia. V. M. Bekhterev review of psychiatry and medical psychology. 2020; (1): 83—92. (In Russ.) doi: 10.31363/2313-7053-2020-1-83-92; 10. Ababkov V. A., Babin S. M., Isurina G. L. et al. Application of the Giessen Somatic Complaints Inventory in the clinic of borderline neuropsychiatric and psychosomatic disorders. SPb.; 1993. 24 p. (In Russ.); 11. Rai S. K., Yazdany J., Fortin P. R., Aviсa-Zubieta A. Approaches for estimating minimal clinically important differences in systemic lupus erythematosus. Arthritis Res. Ther. 2015; 17(1): 143—151. doi: 10.1186/s13075-015-0658-6; 12. Copay A. G., Subach B. R., Glassman S. D. et al. Understanding the minimum clinically important difference: a review of concepts and methods. Spine J. 2007; 7: 541—546. doi: 10.1016/j.spinee.2007.01.008; 13. Тomaschik T.E., Assanovich M. A. Psychometric analysis and modification of the Giessen Somatic Complaints Inventory. Journal of Grodno State Medical University. 2022; 20(2): 204—208. (In Russ.) doi: 10.25298/2221-8785-2022-20-2-204-208; 14. Тomaschik T. E. Interpretation criteria for the Giessen Somatic Complaints Inventory based on the Rasch Metric System. In: Actual problems of medicine: collection of materials of the final scientific and practical conference (January 27, 2022). Grodno; 2022. (In Russ.); 15. Assanovich M. A. Method for determining threshold criteria in clinical rating scales developed on the basis of the Rasch model. Psychiatry and Psychopharmacotherapy. 2017; 18(3): 19—24. (In Russ.)