21 A Comparison of the Memory and Non-Memory Based Performance Validity Measures for Detecting Invalid Neuropsychological Test Performance among Individuals with and without Memory Impairment

Abstract

Objective:Few to no studies have directly compared the relative classification accuracies of the memory-based (Brief Visuospatial Memory Test-Revised Recognition Discrimination [BVMT-R RD] and Rey Auditory Verbal Learning Test Forced Choice [RAVLT FC]) and non-memory based (Reliable Digit Span [RDS] and Stroop Color and Word Test Word Reading trial [SCWT WR]) embedded performance validity tests (PVTs). This study’s main objective was to evaluate their relative classification accuracies head-to-head, as well as examine how their psychometric properties may vary among subgroups with and without genuine memory impairment.Participants and Methods:This cross-sectional study included 293 adult patients who were administered the BVMT-R, WAIS-IV Digit Span, RAVLT and SCWT during outpatient neuropsychological evaluation at a Midwestern academic medical center. The overall sample was 58.0% female, 36.2% non-Hispanic White, 41.3% non-Hispanic Black, 15.7% Hispanic, 4.8% Asian/Pacific Islander, and 2.0% other, with a mean age of 45.7 (SD=15.8) and a mean education of 13.9 years (SD=2.8). Three patients had missing data, resulting in a final sample size of 290. Two hundred thirty-three patients (80%) were classified as having valid neurocognitive performance and 57 (20%) as having invalid neurocognitive performance based on performance across four independent, criterion PVTs (i.e., Test of Malingering Memory Trial 1, Word Choice Test, Dot Counting Test, Medical Symptom Validity Test). Of those with valid neurocognitive performance, 76 (48%) patients were considered as having genuine memory impairment through a memory composite band score (T<37 for (RAVLT Delayed Recall T-score + BVMT-R Delay Recall T-score/2).Results:The average memory composite band score for valid neurocognitive scores was T = 49.63 as compared to T = 27.57 for genuine memory impairment individuals. Receiver operating characteristic [ROC] curve analyses yielded significant areas under the curve (AUCs=.79-.87) for all four validity indices (p’s < .001). When maintaining acceptable specificity (91%-95%), all validity indices demonstrated acceptable yet varied sensitivities (35%-65%). Among the subgroup with genuine memory impairment, ROC curve analyses yielded significantly lower AUCs (.64-.69) for three validity indices (p’s < .001), except RDS (AUC=.644). At acceptable specificity (88%-93%), they yielded significantly lower sensitivities across indices (19%-39%). In the current sample, RAVLT FC and BVMT-R RD had the largest changes in sensitivities, with 19% and 26% sensitivity/90%-92% specificity at optimal cut-scores of <10 and <2, respectively, for individuals with memory impairment, compared to 65% and 61% sensitivity/94% specificity at optimal cut-scores of <13 and <4, respectively, for those without memory impairment.Conclusions:Of the four validity scales, memory-based embedded PVTs yielded higher sensitivities while maintaining acceptable specificity compared to non-memory based embedded PVTs. However, they were also susceptible to the greatest declines in sensitivity among the subgroup with genuine memory impairment. As a result, careful consideration should be given to using memory-based embedded PVTs among individuals with clinically significant memory impairment based on other sources of information (e.g., clinical history, behavioral observation).