Rasch analysis and item reduction of the Chinese version of the 20-item Toronto alexithymia scale (TAS-20-C) for adolescents

Introduction: The TAS-20 is a psychometrically validated instrument for assessing alexithymia in adult populations. However, the instrument is not well-established in adolescents. -Objective and aims: The objective of this study was to validate the Chinese version of the TAS-20 (TAS-20-C). Two studies aimed to produce a short form of the TAS-20-C and evaluate its subsequent factor structure in a sample of Chinese adolescents across different grade levels using confirmatory factor analysis (CFA). -Methods: The Mandarin version of the TAS-20-C was modified with respect to the local colloquial and was tested in two separate samples of Chinese adolescents. In Study 1 (n = 500), Rasch modelling and principal component analysis (PCA) were performed to generate a short form of the TAS-20-C and to assess the psychometric properties of the scale. In Study 2 (n = 1294), CFA assessed the fit of the factor structure derived from Study 1. Factorial invariance was also examined across grade levels using multigroup CFA. -Results: Results of Rasch analysis showed 9 items of the TAS-20-C retained the concepts of the original scale, resulting in a 9-item short form (TAS-9-C). PCA yielded a one-factor solution (accounting for 38% of the total variance, r>/ = 0.40). In addition, results of CFA confirmed the one-factor model and its invariance across different grade levels (CFI>/ = 0.959). Internal consistency was good in the entire sample (alpha = 0.83). -Conclusions: The TAS-9-C is a reliable and valid instrument for use in adolescents across different grade levels. Future research on the specific role of alexithymia in explaining childhood psychopathology is desirable.