M is For Performance Validity: The IOP-M Provides a Cost-Effective Measure of the Credibility of Memory Deficits during Neuropsychological Evaluations

Abstract

ABSTRACT This study was designed to evaluate the classification accuracy of the Memory module for the Inventory of Problems (IOP-M) in a sample of real-world patients. Archival data were collected from a mixed clinical sample of 90 adults clinically referred for neuropsychological testing. The classification accuracy of the IOP-M was computed against psychometrically defined invalid performance. IOP-M ≤30 produced a good combination of sensitivity (.46-.75) and specificity (.86-.95). Lowering the cutoff to ≤29 improved specificity (.94-1.00) at the expense of sensitivity (.29-.63). The IOP-M correctly classified between 73% and 91% of the sample. Given its low cost, ease of administration/scoring in combination with robust classification accuracy, the IOP-M has the potential to expand the existing toolkit for the evaluation of performance validity during neuropsychological assessments.