Analysis of psychometric properties of the method "interpretation of proverbs" used to assess thinking disorder in patients with schizophrenia
The purpose of this study was to carry out the Rasch analysis of psychometric properties of the method «Interpretation of proverbs» used to assess thinking disorder in patients with schizophrenia. The difficulty of the questions was considered, the construct validity was estimated, the reliability coefficients and discriminative index were calculated. The study involved 122 patients. All patients met the criteria for schizophrenia. The following results were obtained: the method was transformed to the 10-item one; as a result, there was obtained the optimal combination of psychometric indices: one-dimensional structure, satisfactory construct validity, high reliability, sufficient discriminative index, and adequate accordance of distribution of diagnostic difficulties of return categories of the items and estimated levels of thinking disorder.