COSMIN systematic review and meta-analysis of the measurement properties of the Positive and Negative Syndrome Scale (PANSS)

Background: The Positive and Negative Syndrome Scale (PANSS) is the most widely used tool for assessing the symptoms of schizophrenia. Despite its widespread use, the psychometric properties of the PANSS have not been systematically reviewed. This study fills that gap in the scientific literature. Methods: We utilized 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 in its original three-subscale form as well as the quality level of the evidence available. On this basis we formulated recommendations for future research and use. A study protocol was registered under 10.17605/OSF.IO/5EGMD. The search period was until February 21, 2024. Findings: We included 119 publications. According to COSMIN, the PANSS demonstrated sufficient reliability, construct validity, and responsiveness; but had significant shortcomings in content validity and structural validity. The original three-factor model showed poor structural validity, leading to its COSMIN classification as "not recommendable". The subscales showed overall acceptable measurement properties. However, the lack of structural validity of the three-subscale model renders its subscales less useful. Moreover, the PANSS negative subscale does not cover all domains of the National Institute of Mental Health consensus. Due to the length of the instrument (30-50 min), it is barely useable in clinical practice. Interpretation: Although the PANSS is the standard scale for schizophrenia symptom severity, its shortcomings regarding fundamental psychometric domains and practical applicability warrant the development of new scales for which appropriate methods should be applied from the start. Funding: There was no specific funding source for this research.