Validation of a European Spanish-version of the Self-Evaluation of Negative Symptoms (SNS) in patients with schizophrenia

Leticia García-Álvarez; Clara Martínez-Cao; Teresa Bobes-Bascarán; Almudena Portilla; Philippe Courtet; Lorena de la Fuente-Tomás; Ángela Velasco; Leticia González-Blanco; Paula Zurrón-Madera; Eduardo Fonseca-Pedrero; Pilar A Sáiz; María Paz García-Portilla; Julio Bobes

doi:10.1016/j.rpsmen.2022.01.005

Validation of a European Spanish-version of the Self-Evaluation of Negative Symptoms (SNS) in patients with schizophrenia

Rev Psiquiatr Salud Ment (Engl Ed). 2022 Jan-Mar;15(1):14-21. doi: 10.1016/j.rpsmen.2022.01.005.

Affiliations

¹ Departamento de Psiquiatría, University of Oviedo, Oviedo, Spain; Institute of Health Research of Principado de Asturias (ISPA), Oviedo, Spain; Institute of Neurosciences of Principado de Asturias (INEUROPA), Oviedo, Spain; Centre for Biomedical Research in Mental Health (CIBERSAM), Spain.
² Departamento de Psiquiatría, University of Oviedo, Oviedo, Spain; Institute of Health Research of Principado de Asturias (ISPA), Oviedo, Spain; Institute of Neurosciences of Principado de Asturias (INEUROPA), Oviedo, Spain.
³ Departamento de Psiquiatría, University of Oviedo, Oviedo, Spain; Institute of Health Research of Principado de Asturias (ISPA), Oviedo, Spain; Institute of Neurosciences of Principado de Asturias (INEUROPA), Oviedo, Spain; Centre for Biomedical Research in Mental Health (CIBERSAM), Spain; Health Service of Principado de Asturias (SESPA), Oviedo, Spain.
⁴ Departamento de Psiquiatría, University of Oviedo, Oviedo, Spain; Health Service of Principado de Asturias (SESPA), Oviedo, Spain.
⁵ University of Montpellier, Montpellier, France.
⁶ Centre for Biomedical Research in Mental Health (CIBERSAM), Spain; Departamento Ciencias de la Educación, Universidad de la Rioja, Longroño, Spain.
⁷ Departamento de Psiquiatría, University of Oviedo, Oviedo, Spain; Institute of Health Research of Principado de Asturias (ISPA), Oviedo, Spain; Institute of Neurosciences of Principado de Asturias (INEUROPA), Oviedo, Spain; Centre for Biomedical Research in Mental Health (CIBERSAM), Spain; Health Service of Principado de Asturias (SESPA), Oviedo, Spain. Electronic address: albert@uniovi.es.

PMID: 35256068
DOI: 10.1016/j.rpsmen.2022.01.005

Abstract

Introduction: Negative symptoms can be grouped into five domains: apathy/avolition, anhedonia, asociality, alogia, and affective flattening. There are few validate self-rated measures that assess these five dimensions. Therefore, this study aimed to validate the Self-Evaluation of Negative Symptoms (SNS) in Spanish patients with schizophrenia.

Material and methods: Cross-sectional, validation study in 104 outpatients with schizophrenia evaluated using the Spanish version of the following scales: Clinical Assessment Interview for Negative Symptoms (CAINS), Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Scale for Schizophrenia (CGI-SCH), Personal and Social Performance (PSP), Motivation and Pleasure Scale - Self-Report (MAP-SR), 36-item Short-Form Health Survey (SF-36) and the Self-Evaluation of Negative Symptoms (SNS).

Results reliability: Internal consistency (Cronbach's alpha) was 0.915. Convergent validity: The Pearson correlation coefficient between MAP-SR and SNS Total scores was 0.660 (p<0.001). For PANSS-N, the correlation was 0.437 (p<0.005) and with the CAINS-Total was 0.478 (p<0.005). Divergent validity: The Pearson correlation coefficient between SNS and PSP was r=-0.372 (p≤0.001), and with SF-36 Physical and Mental Summary Component scores were r=-0.213 (p=0.066) and r=-0.144 (p=0.219), respectively. Discriminant validity: SNS Total scores were significantly statistically different according to the severity of the negative symptomatology rated by the CGI-SCH negative scale (p<0.001).

Conclusion: The SNS is a reliable and valid instrument to self-rate the five domains of negative symptoms in patients with schizophrenia and seems to be appropriate for use in everyday clinical practice as a complementary measure to the evaluation performed by the clinician.

Keywords: Autoevaluación; Esquizofrenia; Negative symptoms; Propiedades psicométricas; Psychometric properties; SNS; Schizophrenia; Self-assessment; Síntomas negativos.

MeSH terms

Cross-Sectional Studies
Diagnostic Self Evaluation
Humans
Psychiatric Status Rating Scales
Psychometrics
Reproducibility of Results
Schizophrenia* / diagnosis