T22. CLINICAL VALIDATION OF THE SIX-ITEM POSITIVE AND NEGATIVE SYNDROME SCALE (PANSS-6)

Abstract

Background: Schizophrenia is a severe mental disorder requiring multimodal treatment. Monitoring the severity of schizophrenia during treatment is essential for a successful outcome. The most widely used schizophrenia rating scale is the 30-item Positive and Negative Syndrome Scale (PANSS-30), which takes approximately one hour to administer. This is too time-consuming for routine clinical use. Recently, our group has extracted a 6-item scale (PANSS-6), which has shown solid psychometric properties. The scale consists of the following items: P1 - Delusions, P2 - Conceptual disorganization, P3 - Hallucinatory behavior, N1 -Blunted Affect, N4 - Passive/apathetic social withdrawal and N6 - Lack of spontaneity and flow of conversation. Subsequently, our group produced a brief semi-structured interview, the Simplified Negative and Positive Symptoms Interview (SNAPSI), which can be used to collect information for PANSS-6 rating. Hypotheses: PANSS-6 ratings obtained using the SNAPSI are clinically and psychometrically valid measures for the severity of schizophrenia and tap into the core construct of the full PANSS-30. Methods: Altogether, 75 patients with a diagnosis of schizophrenia, currently undergoing inpatient treatment will be recruited. The SNAPSI and the structured clinical interview for PANSS (SCI-PANSS) will be conducted by independent interviewers followed by independent PANSS-6 and PANSS-30 ratings at two time-points: as soon as possible after admission and as close to discharge as possible. Statistical analyses: The degree to which PANSS-6 (rated independently using the SNAPSI) correspond to PANSS-6 extracted from PANSS-30 (rated using the SCI-PANSS) will be tested by means of intra-class correlation coefficient analysis. The scalability of PANSS-6 will be tested by means of Mokken analysis. Results: At present (November 2018), 40 patients have included in the study. We expect to have included all 75 patients by the end of March so that the initial analysis of the study can be presented at the SIRS 2019 conference. Discussion: If our studies confirm that SNAPSI allows for a valid PANSS-6 measurement of the severity of schizophrenia without additional information from performing the interview on the remaining 24 PANSS-30 items, this holds promise to improve the treatment of schizophrenia by paving the way for implementation of measurement-based care. Implementation of measurement-based care for schizophrenia in real-world settings relies on the development of a brief and feasible rating scale that captures the severity of core aspects of the illness. We believe that the combination of SNAPSI and PANSS-6 is a prime candidate to fill this void.