Rasch analysis and application research of the Chinese version of the Skidmore anxiety stigma scale: a cross-sectional study

Stigma is a prevalent sociocultural phenomenon that substantially negatively affects individuals with anxiety disorders. This study aimed to evaluate the psychometric properties of the Skidmore Anxiety Stigma Scale (SASS) using Rasch analysis and to employ this instrument in assessing stigma among Chinese adults diagnosed with anxiety disorders. The Rasch analysis incorporated multiple psychometric evaluations. Additionally, multiple linear regression analysis was used to identify factors independently associated with stigma. Rasch analysis demonstrated that the 6-item Chinese version of the SASS showed good measurement properties. It demonstrated unidimensionality, with well-fitting items and logically ordered response categories. Differential item functioning analysis revealed cross-gender measurement invariance. The results showed that family history of mental illness (β=-0.277, P < 0.001), objective support (β=-0.357, P < 0.001), and subjective support (β = 0.330, P < 0.001) were significantly associated with stigma. In summary, the psychometric evaluation results of the Chinese SASS met standard criteria, supporting its use as a valid tool for assessing anxiety stigma.