PSYCHOMETRIC ESTIMATION OF THE SCALE FOR THE ASSESSMENT OF THOUGHT DISORDER SEVERITY IN SCHIZOPHRENIA DEVELOPED ON THE BASIS OF "THE SIMILARITY" METHOD

Introduction: The analysis of the scale for the assessment of thought disorder severity in schizophrenia developed on the basis of the “Similarity” method included construction of the equal-interval logit scale using the Rasch model, consideration of the difficulty of the questions, estimation of construct validity and reliability coefficients. Aim: To develop and analyze psychometric parameters of the scale for the assessment of thought disorder severity in schizophrenia based on the “Similarity” method. Material and methods: A total of 122 patients meeting the criteria for schizophrenia were studied using the “Similarity” method. Conclusions: Transformation of dimensional scores into the logit scale was performed. There were no too difficult or too easy questions on the scale. Construct validity was improved after exclusion of two items. Reliability coefficients and discriminative index of the scale were satisfactory.