A-181 Do Effortful Epilepsy Patients Fall Below Performance Validity Test Cutoffs at Higher Rates than Is Considered Acceptable?

Objective Factors specific to an epilepsy population (e.g., medications, psychiatric comorbidities, localization) may result in higher false positive rates on performance validity tests (PVT), rendering the results more equivocal. This study examined whether specificity is reduced in effortful epilepsy patients on the Warrington Recognition Memory Test - Words (WRMT-W) and Test of Memory Malingering (TOMM). Method 53 epilepsy patients referred for neuropsychological evaluation through the University of Washington Regional Epilepsy Center were examined. Patients were majority male (56.6%) and Caucasian (79.2%). Average age and education were 36.1 (SD = 13.03) and 13.4 years (SD = 2.39), respectively. Patients with an intelligence quotient of <70, history of brain surgery, and those who seized during testing were excluded. Patients clinically observed to have reduced effort with 2+ PVT failures were excluded (n = 3). Frequency tables for WRMT-W and TOMM performances were utilized to examine specificity based on prior cutoffs identified for these measures. Results The WRMT-W cutoff of ≤42 was associated with 88.7% specificity. TOMM Trial 2 and Retention cutoffs of <45 were associated with 98.1% and 100% specificity, respectively. The WRMT-W cutoff was associated with 91.7% specificity in language dominant hemisphere onset epilepsy patients (n = 16). None performed below cutoffs on the TOMM. All nondominant hemisphere onset patients (n = 8) performed above WRMT-W and TOMM cutoffs. Conclusions Use of the WRMT-W and TOMM in an epilepsy population is associated with an acceptable false positive rate (specificity around 90%). However, future studies examining the sensitivity of these measures in epilepsy patients should be performed.

A-215 The Utility of the First Ten Items of the Warrington Recognition Memory Test as a Performance Validity Test

Objective Performance validity tests (PVTs) are widely used in neuropsychological evaluations but are often lengthy and time-consuming. Therefore, development of more efficient PVTs is critical. The current study evaluated the utility of the first 10 items of the Warrington Recognition Memory Test (RMT) as an indicator of performance validity. Methods This study utilized archival data from 134 veterans presenting for a clinical neuropsychological evaluation at a southeastern Veterans Affairs hospital. Patients were deemed “credible” if they failed less than two unrelated PVT measures, had a FSIQ > 70, and did not carry a diagnosis of dementia. This resulted in 103 patients in the credible group [Mage = 49.76(11.67); Meducation = 14.09(2.88); 77.67% Male]. The 31 patients in the non-credible group met Slick et al. (1999) criteria[Mage = 45.13(11.18); Meducation = 12.77(2.53); 87.10% Male]. Frequency counts were run to determine sensitivity and specificity values at established cut-offs and to create new cut-offs for the first 10 items. Results Using established cut-off scores, the RMT total score had adequate specificity (91%) with a corresponding sensitivity of 84%, and the RMT time score had adequate specificity (93%) with a corresponding sensitivity of 34%. When examining the first 10 items on the RMT, a score of < 8 resulted in 96% specificity and 61% sensitivity. Conclusions The established cutoffs for the RMT performed well in this patient sample. Additionally, using a cutoff score of ≤ 8 on the first 10 items of the RMT may be a useful indicator of probable failure on the RMT, significantly reducing test administration time.