A positive take on schizophrenia negative symptom scales: Converting scores between the SANS, NSA and SDS

Adrian Preda; Dana D Nguyen; Juan R Bustillo; Aysenil Belger; Daniel S O'Leary; Sarah McEwen; Shichun Ling; Lawrence Faziola; Daniel H Mathalon; Judith M Ford; Steven G Potkin; FBIRN; Theo G M van Erp

doi:10.1016/j.schres.2018.06.014

A positive take on schizophrenia negative symptom scales: Converting scores between the SANS, NSA and SDS

Schizophr Res. 2018 Nov:201:113-119. doi: 10.1016/j.schres.2018.06.014. Epub 2018 Jun 20.

Authors

Adrian Preda¹, Dana D Nguyen², Juan R Bustillo³, Aysenil Belger⁴, Daniel S O'Leary⁵, Sarah McEwen⁶, Shichun Ling⁷, Lawrence Faziola⁷, Daniel H Mathalon⁸, Judith M Ford⁹, Steven G Potkin⁷; FBIRN¹⁰; Theo G M van Erp¹¹

Affiliations

¹ Department of Psychiatry and Human Behavior, University of California Irvine, Irvine, CA, USA. Electronic address: apreda@uci.edu.
² Department of Pediatrics, University of California Irvine, Irvine, CA, USA.
³ Department of Psychiatry, University of New Mexico, Albuquerque, NM, USA.
⁴ Department of Psychiatry and Psychology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
⁵ Department of Psychiatry, University of Iowa, Iowa City, IA, USA.
⁶ Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093, USA.
⁷ Department of Psychiatry and Human Behavior, University of California Irvine, Irvine, CA, USA.
⁸ Department of Psychiatry, UCSF, San Francisco, San Francisco, CA, USA.
⁹ Department of Psychiatry, UCSF, San Francisco, San Francisco, CA, USA; San Francisco Veterans Affairs Medical Center, San Francisco, CA 94121, USA.
¹⁰ Function Biomedical Informatics Research Network, USA.
¹¹ Clinical Translational Neuroscience Laboratory, Department of Psychiatry and Human Behavior, University of California Irvine, Irvine, CA, USA.

Abstract

Aims: To provide quantitative conversions between commonly used scales for the assessment of negative symptoms in schizophrenia.

Method: Linear regression analyses generated conversion equations between symptom scores from the Scale for the Assessment of Negative Symptoms (SANS), the Schedule for the Deficit Syndrome (SDS), the Positive and Negative Syndrome Scale (PANSS), or the Negative Symptoms Assessment (NSA) based on a cross sectional sample of 176 individuals with schizophrenia. Intraclass correlations assessed the rating conversion accuracy based on a separate sub-sample of 29 patients who took part in the initial study as well as an independent sample of 28 additional subjects with schizophrenia.

Results: Between-scale negative symptom ratings were moderately to highly correlated (r = 0.73-0.91). Intraclass correlations between the original negative symptom rating scores and those obtained via using the conversion equations were in the range of 0.61-0.79.

Conclusions: While there is a degree of non-overlap, several negative symptoms scores reflect measures of similar constructs and may be reliably converted between some scales. The conversion equations are provided at http://www.converteasy.org and may be used for meta- and mega-analyses that examine negative symptoms.

Keywords: Conversion; Meta-; Multi-center; Multi-site; NSA; Negative symptoms; PANSS; SANS; SDA; Schizophrenia.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Adult
Cross-Sectional Studies
Female
Humans
Male
Psychiatric Status Rating Scales*
Regression Analysis
Reproducibility of Results
Schizophrenia / diagnosis*
Schizophrenic Psychology*

Abstract

Publication types

MeSH terms

Grants and funding