Replication and cross-validation of the personality assessment inventory (PAI) cognitive bias scale (CBS) in a mixed clinical sample.

This study is a cross-validation of the Cognitive Bias Scale (CBS) from the Personality Assessment Inventory (PAI), a ten-item scale designed to assess symptom endorsement associated with performance validity test failure in neuropsychological samples. The study utilized a mixed neuropsychological sample of consecutively referred patients at a large academic medical center in the Midwest. Participants were 332 patients who completed embedded and free-standing performance validity tests (PVTs) and the PAI. Pass and fail groups were created based on PVT performance to evaluate classification accuracy of the CBS. The results were generally consistent with the initial study for overall classification accuracy, sensitivity, and cut-off score. Consistent with the validation study, CBS had better classification accuracy than the original PAI validity scales and a comparable effect size to that obtained in the original validation publication; however, the Somatic Complaints scale (SOM) and the Conversion subscale (SOM-C) also demonstrated good classification accuracy. The CBS had incremental predictive ability compared to existing PAI scales. The results supported the CBS, but further research is needed on specific populations. Findings from this present study also suggest the relationship between conversion tendencies and PVT failure may be stronger in some geographic locations or population types (forensic versus clinical patients).