The Negative Symptoms Assessment-5 (NSA-5) is clinical assessment tool for measuring the severity of negative symptoms that reflects the modern concept of negative syndrome. The purpose of this study was to conduct a comprehensive psychometric analysis of the Russian-language version of the NSA-5 with the determination of diagnostic criteria for assessing the severity of negative symptoms in the dynamics of treatment in patients with schizophrenia. Psychometric analysis was done on the base of the Rush measurement. Minimum clinically important differences were found using the MDC95% index for each score of the scale. The NSA-5 showed the adequate construct validity of its diagnostic points, the unidimensionality of the structure, high reliability and sensitivity to changes. The scale is able to differentiate 7 metric levels of severity of negative symptoms, diagnostic criteria are suitable for use in clinical practice and scientific research.

Objectives. To assess psychometric properties of Scale for the Assessment of Positive Symptoms (SAPS) and to develop criteria for assessing the severity of positive symptoms in the dynamics of therapy, to clinically verify SAPS metric criteria. Material and methods. The study involved 157 patients with the diagnosis of schizophrenia. Psychometric analysis of SAPS was carried out on the basis of the Rasch metric system with the development of criteria for assessing the severity of positive symptoms based on the index of minimum detectable changes for 95% probability (Minimum detectable change 95% - MDC95%). Clinical verification was conducted by statistical analysis of contingency tables of clinical and metric criteria using the Clinical Global Impression Scale (CGI). Results. All items of SAPS have reasonable level of construct validity. The scale is characterized by moderate reliability (r= 0.84) and high discrimination. Factor analysis has revealed heterogeneity of SAPS metric structure: items in the first group assess hallucinatory and delusional symptoms, items in the second group characterize behavioral disorders and formal thinking disorders. The heterogeneity of SAPS reflects dimensional structure of positive syndrome, which allows to consider total score on the scale as an indicator of this psychopathological construct severity. On the basis of metric approach, criteria for assessing the severity of positive symptoms in the dynamics of therapy have been developed. Statistically significant linear relationship has been found between the levels of SAPS and CGI scales: SAPS has shown higher discriminativeness in assessing severe levels and less marked discriminativeness in assessing low levels of positive symptoms compared to CGI. Conclusions. SAPS has acceptable psychometric characteristics. The developed diagnostic criteria are suitable for the use in clinical practice and research.

Шкала оценки психотических симптомов (The Psychotic Symptom Rating Scales – PSYRATS) является одним из широко используемых инструментов клинической оценки вербальных галлюцинаций и бредовых идей. Цель настоящего исследования состояла в психометрическом анализе и модификации методики PSYRATS с определением критериев оценки выраженности психотических симптомов в динамике терапии пациентов с шизофренией. В исследовании приняли участие 157 пациентов с диагнозом «шизофрения», возрастной диапазон участников составил от 18 до 59 лет. Психометрический анализ проводился на основе метрической системы Раша. Факторный анализ выявил двухфакторную структуру PSYRATS (фактор «вербальных галлюцинаций» AHS и фактор «бредовых идей» DS). Анализ субшкалы AHS продемонстрировал низкую конструктную валидность 2 диагностических пунктов. Проведена модификация AHS путем исключения невалидных пунктов. Модифицированный вариант AHSmod имеет одномерную структуру и отличается высокой надежностью и дискриминативностью. AHSmod способна дифференцировать 8 метрических уровней выраженности вербальных галлюцинаций. Анализ субшкалы DS продемонстрировал адекватную конструктную валидность всех диагностических пунктов, одномерную структуру субшкалы. DS отличается высокой надежностью и способна дифференцировать 6 метрических уровней выраженности бредовых идей. В ходе метрического анализа определены критерии оценки выраженности слуховых галлюцинаций и бредовых идей в динамике проводимой терапии. Модифицированный вариант PSYRAYS обладает адекватными психометрическими характеристиками. Диагностические критерии пригодны для использования в клинической практике и научном исследовании. The Psychotic Symptom Rating Scale is one of the widely used clinical assessment tools for psychotic symptoms. The purpose of this study was psychometric analysis and modification of the PSYRATS with determination of criteria for assessing the severity of psychotic symptoms in the dynamics of therapy in patients with schizophrenia. The study involved 157 patients with the diagnosis of schizophrenia; the age of participants ranged from 18 to 59 years. Psychometric analysis was done on the base of the Rasch measurement. Factor analysis revealed the two-factor structure of the PSYRATS (the factor of “auditory hallucinations” AHS and the factor of “delusional ideas” DS). Analysis of the AHS showed the low construct validity of 2 diagnostic items. The subscale was modified by eliminating the invalid items. The modified version of the AHSmod has a unidimensional structure and demonstrates highly reliable nature and discriminativeness. The AHSmod is able to differentiate 8 metric levels of the severity of auditory hallucinations. Analysis of the DS showed the adequate construct validity of all diagnostic items, the unidimensional structure of the subscale. The DS is highly reliable and is able to differentiate 6 metric levels of the severity of delusional ideas. In the course of the metric analysis, the criteria for assessing the severity of auditory hallucinations and delusion ideas in the dynamics of the therapy were determined. The modified version of PSYRATS has adequate psychometric characteristics. The diagnostic criteria are suitable for use in clinical practice and research.

Topicality. Search for scientifically based criteria for symptomatic remission and outcomes in schizophrenia is an urgent problem in modern psychiatry. Aim. To determine predictors of therapeutic response and duration of hospitalization during the course of psychopharmacotherapy in patients with schizophrenia. Material and methods. Clinical and metric examination using scales for assessing severity of positive (SAPS, PSYRATS, BABS) and negative (SANS, NSA-5) symptoms was performed in 157 patients with a diagnosis of schizophrenia twice: on admission to hospital and after the course of psychopharmacotherapy. The model for predicting therapeutic response was built using logistic regression, the model for predicting duration of hospitalization was built using linear regression using metrically justified criteria for achieving a significantly low level of severity of positive and negative symptoms as criteria for a significant therapeutic response. Results. The predictors were determined that increase and decrease likelihood of therapeutic response for scales for assessing positive and negative symptoms in patients with schizophrenia during the course of psychopharmacotherapy. Conclusions. Therapeutic response prediction models for scales for assessing the severity of positive symptoms and scales for the severity of negative symptoms are of good quality and high diagnostic value.