Latent structure and differential item functioning of the Social Interaction Anxiety Scale (SIAS-6) in college alcohol consumers

The aim of this study was to analyze the structure of the SIAS-6 from an integrative approach of psychological network analysis and item response theory (IRT). In addition, differential item functioning (DIF) was identified as a function of gender. In this regard, an exploratory graph analysis (EGA) followed by a Bootstrap (bootEGA) was applied to assess the stability and consistency of items and dimensions. Then, a graduated response IRT model with discrimination and difficulty parameters was used and complemented with a DIF analysis. The results showed a community with structural consistency and replicable stability in the various resamplings. From IRT, the model reflected a unidimensionality measure (RMSEA = 0.047 [95%CI, 0.027/0.068], SRMR = 0.025, TLI = 0.993, CFI = 0.995). Item 5 was the most discriminant and most accurate; while item 6 provided less information, but presented greater difficulty. Only item 6 showed DIF with minimal effect size with higher scores in favor of the female group. Additionally, the association between the SIAS-6 and depression was of minimal effect size (Rho = 0.44). It is concluded that the SIAS-6 is a unidimensional instrument applicable to male and female college students with alcohol consumption in an educational context.