Converting positive and negative symptom scores between PANSS and SAPS/SANS

Abstract

The Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), and the Positive and Negative Syndrome Scale for Schizophrenia (PANSS) are the most widely used schizophrenia symptom rating scales, but despite their co-existence for 25 years no easily usable between-scale conversion mechanism exists. The aim of this study was to provide equations for between-scale symptom rating conversions. Two- hundred-and-five schizophrenia patients [mean age±SD=39.5±11.6), 156 males] were assessed with the SANS, SAPS, and PANSS. Pearson’s correlations between symptom scores from each of the scales were computed. Linear regression analyses, on data from 176 randomly selected patients, were performed to derive equations for converting ratings between the scales. Intraclass correlations, on data from the remaining 29 patients, not part of the regression analyses, were performed to determine rating conversion accuracy. Between-scale positive and negative symptom ratings were highly correlated. Intraclass correlations between the original positive and negative symptom ratings and those obtained via conversion of alternative ratings using the conversion equations were moderate to high (ICCs = 0.65 to 0.91). Regression-based equations may be useful for conversion between schizophrenia symptom severity as measured by the SANS/SAPS and PANSS, though additional validation is warranted. This study’s conversion equations, implemented at http::/converteasy.org, may aid in the comparison of medication efficacy studies, in meta- and mega-analyses examining symptoms as moderator variables, and in retrospective combination of symptom data in multi-center data sharing projects that need to pool symptom rating data when such data are obtained using different scales.

Psychometric evaluation of the negative syndrome of schizophrenia

“…Although they found high correlation coefficients (0.71-0.84), they concluded that further studies are needed in order to validate these equations [30].…”

“…Recently, van Erp et al [30] have developed conversion equations between scores on the SANS and PANSS-NS and PANSS-NF. Although they found high correlation coefficients (0.71-0.84), they concluded that further studies are needed in order to validate these equations [30].…”

Theta response in schizophrenia is indifferent to perceptual illusion

“…The educational level was assessed by rating the school leaving certificate between 1 (below highschool) to 4 (university-entrance diploma). Psychopathologic signs were measured by the Scale for the Assessment of Negative Symptoms (SANS) and by the Scale for the assessment of Positive Symptoms (SAPS, Andreasen, 1990;van Erp et al, 2014, see table 1 for details).…”

Episodic foresight and schizophrenia

“…For interested readers, who wish to directly compare the symptom scores of the present schizophrenia group with other studies that have used the Positive and Negative Syndrome Scale for Schizophrenia (PANSS), equations have recently been provided for between-scale symptom rating conversions between the SANS, SAPS, and PANSS(van Erp et al, 2014).…”