COSMIN systematic review and meta-analysis of the measurement properties of the PANSS-6

The Positive and Negative Syndrome Scale (PANSS-30) is the standard instrument for assessing symptoms of schizophrenia and related psychotic disorders. However, its long administration time and structural issues have prompted the development of shorter versions. The PANSS-6, derived through Item Response Theory and Rasch analysis of the PANSS-8, emerged as a potential alternative. Comprising three positive and three negative symptom items, the PANSS-6 offers a more feasible assessment tool. However, its measurement properties have never been systematically reviewed. We applied the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guideline for systematic reviews and meta-analytical procedures to assess the psychometric properties of the PANSS-6. COSMIN comprises several steps: literature search, risk-of-bias assessments, assessing the updated criteria for good measurement properties, grading the quality of the evidence and feasibility aspects. We included 13 publications. The PANSS-6 showed sufficient content validity, structural validity, measurement invariance, reliability, criterion validity, construct validity and responsiveness according to COSMIN. On some of them only a small body of evidence is currently available. For internal consistency, cross-cultural validity and measurement error there was not enough evidence for a definite rating. Its short administration time of only 15-20 mins renders feasibility good. The PANSS-6 does not cover all schizophrenia symptoms but focuses on the core symptoms in favor of a feasible administration time. The evidence available on its measurement properties yields sufficient results for its purpose - the assessment of symptom severity and its change. According to COSMIN it can potentially be recommended for use.