Cross-cultural psychometric assessment of the VAGUS insight into psychosis scale - Spanish version

Abstract

Impaired insight into illness, a core feature of schizophrenia with negative clinical implications, is a multidimensional phenomenon existing on a continuum. However, the degree to which illness perception in distinct cultures influences the appraisal of insight into illness in schizophrenia remains unclear. As such, we aimed to determine if the psychometric properties of the VAGUS insight into psychosis scale (www.vagusonline.com), which was originally assessed in English speaking Canadians, were similar in a sample of Latino Mexican Spanish speaking patients with schizophrenia. To accomplish this, the VAGUS - Self-Report (SR) version was translated from English to Spanish and psychometrically evaluated in 95 participants. The Spanish version of the VAGUS-SR was internally consistent (ᾳ = 0.713), and demonstrated good convergent and discriminant validity with the subscales of the Positive and Negative Syndrome Scale. Factor analysis identified two components of insight, congruent with two of the components of the English version of the VAGUS-SR. In conclusion, the VAGUS-SR is a brief, novel, and valid measure of insight into illness in schizophrenia, which demonstrated similar psychometric properties in two culturally and linguistically distinct samples with schizophrenia. Future studies should assess whether the VAGUS demonstrates similar psychometric properties in non-Western cultures.

Keywords: Culture; Illness Awareness; Insight; Schizoaffective disorder; Schizophrenia; Spanish; Symptom assessment.