Research methods in performance validity testing studies: Criterion grouping approach impacts study outcomes.

OBJECTIVE: Performance validity test (PVT) research studies commonly utilize a known-groups design, but the criterion grouping approaches within the design vary greatly from one study to another. At the present time, it is unclear as to what degree different criterion grouping approaches might impact PVT classification accuracy statistics. METHOD: To analyze this, the authors used three different criterion grouping approaches to examine how classification accuracy statistics of a PVT (Word Choice Test; WCT) would differ. The three criterion grouping approaches included: (1) failure of 2+ PVTs versus failure of 0 PVTs, (2) failure of 2+ PVTs versus failure of 0-1 PVT, and (3) failure of a stand-alone PVT versus passing of a stand-alone PVT (Test of Memory Malingering). RESULTS: When setting specificity at ≥.90, WCT cutoff scores ranged from 41 to 44 and associated sensitivity values ranged from .64 to .88, depending on the criterion grouping approach that was utilized. CONCLUSIONS: When using a stand-alone PVT to define criterion group status, classification accuracy rates of the WCT were higher than expected, likely due to strong correlations between the reference PVT and the WCT. This held true even when considering evidence that this grouping approach results in higher rates of criterion group misclassification. Conversely, when using criterion grouping approaches that utilized failure of 2+ PVTs, accuracy rates were more consistent with expectations. These findings demonstrate that criterion grouping approaches can impact PVT classification accuracy rates and resultant cutoff scores. Strengths, weaknesses, and practical implications of each of the criterion grouping approaches are discussed.

Examination of optimal embedded PVTs within the BVMT-R in an outpatient clinical sample.

OBJECTIVE: This study investigated whether indices within the Brief Visuospatial Memory Test - Revised (BVMT-R) could function as embedded performance validity measures in an outpatient clinical sample. METHOD: A sample of 138 neuropsychological outpatients was utilized; approximately 45% had a known or suspected external incentive. Patients were determined to be valid performers if they passed all criterion performance validity tests (PVTs) and determined to be invalid performers if they failed two or more PVTs. BVMT-R indices met criteria for optimal embedded PVTs if they were not significantly correlated with genuine cognitive dysfunction and if they adequately differentiated the validly from invalidly performing patient groups. Classification accuracy statistics for the indices were then calculated. Supplementary analyses were also calculated for a separate dementia sample. RESULTS: Recognition Hits and Recognition Discrimination were identified as two optimal embedded PVTs for patients without dementia. Recognition Hits showed a sensitivity rate of 41% and a specificity rate of 95%. Recognition Discrimination showed a sensitivity rate of 54% and a specificity rate of 93%. CONCLUSION: Embedded BVMT-R PVTs are discussed in relation to previous research findings, which were obtained from veteran samples. Recognition Hits and Recognition Discrimination are now validated in a non-veteran clinical sample.

Rates of Abnormally Low TOPF Word Reading Scores in Individuals Failing Versus Passing Performance Validity Testing.

The present study examined the impact of performance validity test (PVT) failure on the Test of Premorbid Functioning (TOPF) in a sample of 252 neuropsychological patients. Word reading performance differed significantly according to PVT failure status, and number of PVTs failed accounted for 7.4% of the variance in word reading performance, even after controlling for education. Furthermore, individuals failing ≥2 PVTs were twice as likely as individuals passing all PVTs (33% vs. 16%) to have abnormally low obtained word reading scores relative to demographically predicted scores when using a normative base rate of 10% to define abnormality. When compared with standardization study clinical groups, those failing ≥2 PVTs were twice as likely as patients with moderate to severe traumatic brain injury and as likely as patients with Alzheimer's dementia to obtain abnormally low TOPF word reading scores. Findings indicate that TOPF word reading based estimates of premorbid functioning should not be interpreted in individuals invalidating cognitive testing.

Excessive decline from premorbid functioning: detecting performance invalidity with the WAIS-IV and demographic predictions.

OBJECTIVE: Excessive Decline from Premorbid Functioning (EDPF) is presented as a construct and defined as a discrepancy between predicted premorbid ability and current test performance that is so atypical of individuals with true neurocognitive impairment that it is likely the product of performance invalidity. New embedded PVTs (EDPF-FSIQ, EDPF-VW, and EDPF-PP) were derived by comparing scores from the WAIS-IV to TOPF demographically predicted premorbid estimates and then examined for classification accuracy. PARTICIPANTS AND METHODS: After excluding for dementia, intellectual disability, and left-sided stroke, participants (n = 230) were grouped according to number of PVTs failed. ROC analyses were conducted to determine the accuracy of EDPF indices in classifying patients as failing 0 or ≥2 PVTs within both a mixed neuropsychological outpatient sample and according to specific diagnostic criterion groups. RESULTS: Significant group differences emerged for all EDPF indices (p < .001). EDPF-FSIQ resulted in an AUC of .837, classifying patients with 56% sensitivity at ≥90% specificity, and EDPF-VW resulted in an AUC of .850, classifying patients with 61% sensitivity at ≥90% specificity. Accuracy remained high across diagnostic groups (i.e. neurocognitive, moderate/severe TBI, and psychiatric) for EDPF-VW and EDPF-FSIQ, whereas specificity declined for EDPF-PP in patients with mixed neurocognitive disorders. Overall, classification accuracy rates exceeded those of Reliable Digit Span. CONCLUSIONS: Both EDPF-FSIQ and EDPF-VW demonstrated excellent discrimination between patients providing valid versus invalid test performance. Unique advantages of EDPF validity measures include incorporation of demographic estimates of premorbid ability and examination of performances on multiple tests spanning different cognitive domains.

Comparative prediction of nonepileptic events using MMPI-2 clinical scales, Harris Lingoes subscales, and restructured clinical scales.

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) is a psychological testing tool used to measure psychological and personality constructs. The MMPI-2 has proven helpful in identifying individuals with nonepileptic events/nonepileptic seizures. However, the MMPI-2 has had some updates that enhanced its original scales. The aim of this article was to test the utility of updated MMPI-2 scales in predicting the likelihood of non-epileptic seizures in individuals admitted to an EEG video monitoring unit. We compared sensitivity, specificity, and likelihood ratios of traditional MMPI-2 Clinical Scales against more homogenous MMPI-2 Harris-Lingoes subscales and the newer Restructured Clinical (RC) scales. Our results showed that the Restructured Scales did not show significant improvement over the original Clinical scales. However, one Harris-Lingoes subscale (HL4 of Clinical Scale 3) did show improved predictive utility over the original Clinical scales as well as over the newer Restructured Clinical scales. Our study suggests that the predictive utility of the MMPI-2 can be improved using already existing scales. This is particularly useful for those practitioners who are not invested in switching over to the newly developed MMPI-2 Restructured Form (MMPI-2 RF).

Wernicke-Korsakoff Syndrome as a Consequence of Delusional Food Refusal: A Case Study.

Wernicke-Korsakoff syndrome is caused by thiamine (vitamin B1) deficiency, typically resulting from malnutrition secondary to chronic alcohol abuse. Less often, other conditions can lead to malnutrition and Wernicke-Korsakoff syndrome. We describe a 35-year-old man who developed Wernicke-Korsakoff syndrome with a typical neurologic and neuropsychological presentation after somatic delusions led him to refuse to eat. Cases like his serve to heighten awareness of the interplay between psychiatric and neurologic conditions, their sometimes atypical pathogenesis, and the value to primary care providers of consulting with psychiatrists, neurologists, and neuropsychologists when managing patients with possible Wernicke-Korsakoff syndrome.

Does True Neurocognitive Dysfunction Contribute to Minnesota Multiphasic Personality Inventory-2nd Edition-Restructured Form Cognitive Validity Scale Scores?

Previous research has demonstrated RBS and FBS-r to identify non-credible reporters of cognitive symptoms, but the extent that these scales might be influenced by true neurocognitive dysfunction has not been previously studied. The present study examined the relationship between these cognitive validity scales and neurocognitive performance across seven domains of cognitive functioning, both before and after controlling for PVT status in 120 individuals referred for neuropsychological evaluations. Variance in RBS, but not FBS-r, was significantly accounted for by neurocognitive test performance across most cognitive domains. After controlling for PVT status, however, relationships between neurocognitive test performance and validity scales were no longer significant for RBS, and remained non-significant for FBS-r. Additionally, PVT failure accounted for a significant proportion of the variance in both RBS and FBS-r. Results support both the convergent and discriminant validity of RBS and FBS-r. As neither scale was impacted by true neurocognitive dysfunction, these findings provide further support for the use of RBS and FBS-r in neuropsychological evaluations.

An examination of the frequency of invalid forgetting on the Test of Memory Malingering.

The Test of Memory Malingering (TOMM) is the most used performance validity test in neuropsychology, but does not measure response consistency, which is central in the measurement of credible presentation. Gunner, Miele, Lynch, and McCaffrey (2012) developed the Albany Consistency Index (ACI) to address this need. The ACI consistency measurement, however, may penalize examinees, resulting in suboptimal accuracy. The Invalid Forgetting Frequency Index (IFFI), created for the present study, utilizes an algorithm to identify and differentiate learning and inconsistent response patterns across TOMM trials. The purpose of this study was to assess the diagnostic accuracy of the ACI and IFFI against a reference test (Malingered Neurocognitive Dysfunction criteria), and to compare both to the standard TOMM indexes. This retrospective case-control study used 59 forensic cases from an outpatient clinic in Southern Kansas. Results indicated that sensitivity, negative predictive value, and overall accuracy of the IFFI were superior to both the TOMM indexes and ACI. Logistic regression odds ratios were similar for TOMM Trial 2, Retention, and IFFI (1.25, 1.24, 1.25, respectively), with the ACI somewhat lower (1.18). The IFFI had the highest rate of group membership predictions (79.7%). Implications and limitations of the present study are discussed.

The Coin-in-the-Hand Test and dementia: more evidence for a screening test for neurocognitive symptom exaggeration.

BACKGROUND: The Coin-in-the-Hand Test was developed to help clinicians distinguish patients who are neurocognitively impaired from patients who are exaggerating or feigning memory complaints. Previous findings have shown that participants asked to feign memory problems and patients suspected of malingering performed worse on the test than patients with genuine neurocognitive dysfunction. OBJECTIVE: We reviewed the literature on the Coin-in-the-Hand Test and evaluated test performance by 45 hospitalized patients who had dementia with moderately to severely impaired cognition. METHODS: We analyzed Coin-in-the-Hand Test scores, neuropsychological findings, and other data to determine whether demographic or neurocognitive variables affected Coin-in-the-Hand Test scores. We also calculated base rates of these scores and provided cutoff ranges for clinical use. RESULTS: Coin-in-the-Hand Test scores were independent of neurocognitive functioning, age, education level, and type of dementia. Base rates of scores suggest that a low cutoff can help differentiate between patients with true neurocognitive impairments and those exaggerating or feigning memory complaints. CONCLUSIONS: Both the literature and our findings show the Coin-in-the-Hand Test to have potential as a quick and easy screening tool to detect neurocognitive symptom exaggeration. This test could effectively supplement commonly used neurocognitive screens such as the Mini-Mental State Examination, the Saint Louis University Mental Status Examination, and the Montreal Cognitive Assessment.

Validation of MMPI-2-RF validity scales in criterion group neuropsychological samples.

This study utilized multiple criterion group neuropsychological samples to evaluate the "over-reporting" and "under-reporting" MMPI-2-RF validity scales. The five criterion groups included in this study were (1) litigating traumatic brain injury patients who failed Slick et al. criteria for probable malingering, (2) litigating traumatic brain injury patients who passed Slick et al. criteria, (3) mixed neuropsychological outpatients who passed SVTs and were diagnosed with primary neurological conditions, (4) mixed neuropsychological outpatients who passed SVTs and were diagnosed with primary psychiatric conditions, and (5) epileptic seizure disorder inpatients who were diagnosed via video-EEG. Using the data from these groups, cumulative percentages for all possible T-scores and sensitivity and specificity rates for optimal cutoff scores were determined. When specificity rates were set at 90% across all non-malingering neurological condition groups, sensitivity rates ranged from 48% (FBS-r) to 10% (K-r).

Levetiracetam is associated with improved cognitive outcome for patients with intracranial hemorrhage.

BACKGROUND: To date, common therapy in patients with intracranial hemorrhage (ICH) includes prophylaxis of seizure using antiepileptic drugs, commonly phenytoin. Phenytoin therapy is associated with a high incidence of cognitive disturbance. Levetiracetam is known to cause less cognitive disruption and may be a suitable alternative for seizure prophylaxis. Cognitive outcomes in ICH patients receiving seizure prophylaxis with levetiracetam or phenytoin are compared. METHOD: A retrospective chart review was conducted with 269 patients who received prophylactic levetiracetam or phenytoin between August 2005 and May 2008. A total of 85 reviewed patients met inclusion criteria (phenytoin n = 25, levetiracetam n = 60). RESULTS: Statistically significant results included higher Glasgow Coma Scores (GCS) at dismissal (median, 14 vs. 11, P = 0.023), lower seizure incidence (0.0 vs. 8%, P = 0.03) for patients receiving levetiracetam than those treated with phenytoin and patients being discharged home (21.7% vs. 16%, P = 0.03). Observed trends included greater cognitive function retention rate (56.7% vs. 36%, P = 0.08). CONCLUSION: Despite similarities in hemorrhage type and severity at onset, patients receiving levetiracetam had better cognition at discharge and fewer seizures than patients receiving phenytoin. These data suggest that levetiracetam is more effective than phenytoin for seizure prophylaxis without suppression of cognitive abilities in patients with ICH.