Validation of the Chinese version of the Valued Living Questionnaire among Chinese patients with psychiatric illness

Background: Valued living is a core process in Acceptance and Commitment Therapy (ACT), and the Valued Living Questionnaire (VLQ) is widely used to assess this construct. However, the psychometric properties of the Chinese version of the VLQ (VLQ-C) have not been established. This study aimed to translate the VLQ into Chinese and evaluate its psychometric properties using complementary Item Response Theory (IRT) and Classical Test Theory (CTT) approaches. Methods: The VLQ was translated and culturally adapted in accordance with international guidelines. Face and content validity were established prior to administration among 300 Chinese-speaking patients with psychiatric illness. Reliability was assessed using ordinal Cronbach's alpha, McDonald's omega, and test-retest reliability. Convergent and discriminant validity were evaluated using the Chinese versions of the Acceptance and Action Questionnaire-II (AAQ-II-C) and Generalized Anxiety Disorder-7 (GAD-7-C), respectively. Rasch Partial Credit Model (PCM) analysis was performed to evaluate category functioning, item fit, reliability, separation, and targeting. Polychoric confirmatory factor analysis (CFA) using robust weighted least squares mean, and variance adjusted estimation (WLSMV) was conducted to compare competing factorial structures. Results: The VLQ-C showed excellent face/content validity. Internal consistency was good to excellent (α = 0.834-0.935; ω = 0.834-0.934), and test-retest reliability was excellent (ICC = 0.826-0.865). Convergent validity was supported by moderate correlations with psychological flexibility (r = 0.501-0.680); discriminant validity by weak negative correlations with anxiety (r = -0.132 to -0.282). Rasch PCM favored a 5-category over the original 10-category format, with better category functioning, item fit, targeting, and model performance. Polychoric CFA supported a two-factor model with correlated residuals as the best-fitting structure. Conclusion: The VLQ-C shows promising psychometric properties for assessing valued living in Chinese-speaking psychiatric patients. Independent validation in clinical and community samples is recommended prior to broader use.