Validation of the factorial structure of the Positive and Negative Syndrome Scale in use by untrained psychiatrists in routine care

Abstract

Background. The Positive and Negative Syndrome Scale (PANSS) can be called the standard for the assessment of schizophrenic disorders. It is well-known and routinely used. In scientific studies and clinical practice extensive training of raters in the use of the scale can often not be provided. The question is whether under such conditions psychometric properties of the scale can be guaranteed. Method. In a 2-year drug utilization study on risperidone, 1895 schizophrenic outpatients were assessed by their treating psychiatrists, who were working under conditions of routine care, using a modified version of the Positive and Negative Symptom Scale (PANSS/m). Physicians could not be trained in the use of the scale. The results of these ratings were analysed, comparing means and internal consistency with the original Kay et al. results (Kay et al. The positive and negative syndrome scale (PANSS) for schizophrenia. Schizophr Bull 1987;13:261), and by factor analysis for the total sample and split halves. Results. Means for the positive subscale were similar (6.5 and 6.4, respectively) and means for the negative subscale (11.9 and 8.0, respectively) slightly higher than the original Kay et al. results. Internal consistency of the positive and negative subscales (0.80 and 0.87, and 0.73 and 0.83, respectively) were similar to Kay et al. The same clear factorial solution was found for the total sample and the subsamples. Discussion. Scores for the subscales reflect the predominance of negative symptoms in schizophrenic outpatients. The factorial solution supports the positive and negative subscales of the PANSS. The PANSS/m was easy to use under conditions of routine treatment and is a good and robust scale.

• schizophrenia
• outpatients
• methods
• reliability and validity
• negative symptoms
• positive symptoms
• risperidone