B - 130 Application of Item Response Theory to the MMPI-2-RF Response Bias Scale-19 (RBS-19)

Abstract

Abstract Objective RBS is a cognitive overreporting scale on the MMPI-family of instruments. Recent efforts to refine the scale removed nine items lacking conceptual and empirical relationships to cognitive dysfunction (Ingram et al., 2024; Ratcliffe et al., 2022). This revised scale version (RBS-19) demonstrated improved utility and classification accuracy, although the improvements were small. Albertorio et al (2024) found that the RBS could be reduced to 14 items and identified potential “critical items”. This study uses IRT in a database of Active-Duty personnel to explore reduced item RBS forms. Method Using a 2-parameter IRT model, we examined cognitive overreporting across the 19-item MMPI-2-RF RBS-19 Scale. Participants (n = 326; 96% male) were divided into pass-all vs fail 2+ standalone PVTs for criterion-based comparisons (e.g., ROC analysis and mean difference), with indetermined profiles removed. Results Results indicate good theta coverage. Two items (24 and 26) were removed due to low α (2). RBS-14/17/19 all had similar AUC (0.72 vs 0.71 vs 0.72) and similar effect sizes between groups. Conclusions IRT analyses supported a 17-item RBS scale rather than the 14 or 19 item versions in this sample. However, no “critical items” emerged in this sample. Such differences may reflect changes in factor structure based on referral reason (Boress et al., 2023).