The measurement invariance of schizotypy in Europe.
Fonseca-Pedrero EDepartment of Educational Sciences, University of La Rioja, Spain; Prevention Program for Psychosis (P3), Spain. Electronic address: eduardo.fonseca.pedrero@gmail.com.
Ortuño-Sierra JDepartment of Educational Sciences, University of La Rioja, Spain.
Sierro GInstitute of Psychology, University of Lausanne, Switzerland.
Daniel CResearch Department of Clinical, Educational and Health Psychology, University College London, UK.
Cella MDepartment of Psychology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK.
Preti ACenter of Liaison Psychiatry and Psychosomatics, University Hospital, University of Cagliari, Italy, and Centro Medico Genneruxi, Cagliari, Italy.
Mohr CInstitute of Psychology, University of Lausanne, Switzerland.
Mason OJResearch Department of Clinical, Educational and Health Psychology, University College London, UK.
English
The short version of the Oxford-Liverpool Inventory of Feelings and Experiences (sO-LIFE) is a widely used measure assessing schizotypy. There is limited information, however, on how sO-LIFE scores compare across different countries. The main goal of the present study is to test the measurement invariance of the sO-LIFE scores in a large sample of non-clinical adolescents and young adults from four European countries (UK, Switzerland, Italy, and Spain). The scores were obtained from validated versions of the sO-LIFE in their respective languages. The sample comprised 4190 participants (M=20.87 years; SD=3.71 years). The study of the internal structure, using confirmatory factor analysis, revealed that both three (i.e., positive schizotypy, cognitive disorganisation, and introvertive anhedonia) and four-factor (i.e., positive schizotypy, cognitive disorganisation, introvertive anhedonia, and impulsive nonconformity) models fitted the data moderately well. Multi-group confirmatory factor analysis showed that the three-factor model had partial strong measurement invariance across countries. Eight items were non-invariant across samples. Significant statistical differences in the mean scores of the s-OLIFE were found by country. Reliability scores, estimated with Ordinal alpha ranged from 0.75 to 0.87. Using the Item Response Theory framework, the sO-LIFE provides more accuracy information at the medium and high end of the latent trait. The current results show further evidence in support of the psychometric proprieties of the sO-LIFE, provide new information about the cross-cultural equivalence of schizotypy and support the use of this measure to screen for psychotic-like features and liability to psychosis in general population samples from different European countries.