Clinical validation of ratings on the six-item Positive and Negative Syndrome Scale obtained via the Simplified Negative and Positive Symptoms Interview

J Psychopharmacol. 2021 Sep;35(9):1081-1090. doi: 10.1177/0269881121996890. Epub 2021 Mar 28.

Abstract

Background: The six-item version of the Positive and Negative Syndrome Scale (PANSS-6) has shown promise as a brief measure of the severity of core symptoms of schizophrenia. However, since all prior analyses of the PANSS-6 were based on data extracted from studies using the full 30-item PANSS (PANSS-30), it remains unknown whether it is possible to obtain valid information for the PANSS-6 ratings via a brief interview, such as the Simplified Negative and Positive Symptoms Interview (SNAPSI).

Aims: We aimed to validate the PANSS-6 ratings obtained via the SNAPSI using the PANSS-6 scores extracted from the PANSS-30 ratings obtained via the comprehensive Structured Clinical Interview for PANSS (SCI-PANSS) as the gold-standard reference.

Methods: The PANSS-6 ratings based on the SNAPSI and the PANSS-30 ratings based on the SCI-PANSS were conducted by independent raters with established inter-rater reliability.

Results: Seventy-seven inpatients with schizophrenia (Mage = 35.1 ± 11.7 years; males = 57%; paranoid schizophrenia = 75%) participated in the study. The intraclass correlation coefficient (ICC) of the PANSS-6 total scores obtained using the SNAPSI and the PANSS-30-derived PANSS-6 total scores via the SCI-PANSS was 0.77 (p < 0.001). The ICC for the PANSS-6 total score and the PANSS-30-derived PANSS-8 (Andreasen's remission criteria) was 0.75 (p < 0.001). Spearman's rank correlation coefficient for changes in PANSS-6 total scores via the SNAPSI and changes in PANSS-30-derived PANSS-6 total scores was 0.70 (p < 0.001).

Conclusions: Using the SNAPSI to rate the PANSS-6 enables a focused and brief assessment of the severity of core symptoms of schizophrenia, which facilitates measurement-based care and clinical decision making in the treatment of schizophrenia.

Keywords: Schizophrenia; antipsychotic drugs; measurement-based care; psychiatric status rating scales; psychometrics; psychopathology.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Validation Study

MeSH terms

  • Adult
  • Female
  • Humans
  • Male
  • Middle Aged
  • Observer Variation
  • Psychiatric Status Rating Scales / standards*
  • Reproducibility of Results
  • Schizophrenia / physiopathology*
  • Schizophrenia, Paranoid / physiopathology*
  • Schizophrenic Psychology
  • Severity of Illness Index
  • Young Adult