The construction and the initial validation of the Cognitive Bias Scale for the Personality Assessment Inventory.

Objective: This study describes the derivation and initial validation evidence of a novel Personality Assessment Inventory (PAI) scale designed to be sensitive to cognitive response bias, as defined by poor performance on performance validity tests (PVTs), in the context of neuropsychological assessment. The Cognitive Bias Scale (CBS) is a ten-item scale that was designed to discriminate between neuropsychological patients who passed or failed PVTs. Method: In a sample of 306 consecutive mixed neuropsychological outpatients, the CBS was derived by initially selecting items that significantly discriminated participants who passed and failed two or more PVTs, with further item refinement utilizing Item Response Theory methods. Results: Initial validation evidence suggests the CBS outperforms existing PAI symptom validity tests in predicting failure on two or more PVTs. The CBS showed good ability to discriminate between valid and invalid performance validity (Cohen's d = -0.96), with good classification accuracy (area under the curve = 0.72). Conclusions: Study results suggest the CBS may be useful in detecting cognitive response bias in a mixed neuropsychological outpatient sample; however, cross-validation will be necessary to further establish its utility.