Psychometric property of the Chinese version of the core symptom index

Abstract

Parents of children with autism spectrum disorders often undergo psychological distress, impacting the quality of childcare. Screening for psychiatric symptoms among these parents is crucial. The Core Symptom Index (CSI) is widely used to assess general symptoms like depression, anxiety, and somatic symptoms, showing validity and reliability in various populations. However, there is limited research on the validity and reliability of the CSI in the general Chinese population. This study aimed to examine the psychometric properties of the Chinese version of the CSI among parents of children with autism spectrum disorders using Confirmatory Factor Analysis (CFA). Methods: A total of 794 Chinese parents raising children with autism participated in this study. All completed the CSI along with the social inhibition subscale of the Interpersonal Problems Inventory and the Couple Satisfaction Index. Factorial validity was conducted using CFA, hypothesizing a first-order three-factor solution model to fit the data. Various structural models were compared using model fit indices. Convergent and discriminant validity were tested by structural equation modeling and exploring correlations with the social inhibition subscale and the Couple Satisfaction Index. Invariance testing of the CSI was conducted across multiple groups of genders, ages, and educations using CFA. The reliability of the CSI was examined by McDonald’s omega coefficients (Ω) and composite reliability using CFA. Results: The first-order 3-factor solution showed adequate model fit indices ([chi2 = 667.659 (df = 85, N = 794, p ≤ .000)]; CFI = 0.93; TLI = .914 RMSEA = 0.093; SRMR = .050). However, the bifactor model appeared to be the best-fitted model for the data, indicating that the total score of the CSI could represent overall psychiatric symptoms. The CSI significantly correlated with the social inhibition subscale (r = 0.412, p < 0.001), with smaller correlation coefficients with the Couple Satisfaction Index (r = -0.161**, p < 0.001), indicating established convergent and discriminant validity. However, discriminant validity using the structural equation model was not confirmed, as the anxiety and depression dimensions appeared indistinguishable. The Chinese version of the CSI demonstrated high consistency (overall scale: Ω = 0.95; depression: Ω = 0.86; anxiety: Ω = 0.90; somatization: Ω = 0.90). Invariant tests supported scalar invariance levels based on gender and age but only partial invariance for education. Conclusion: Psychometric properties indicate that the Chinese version of the CSI is reliable and valid, making it suitable for measuring depression, anxiety, and somatization symptoms among parents of children with autism spectrum disorders. Further research on other Chinese populations is encouraged.