Malingering and mild brain injury: how low is too low

Evaluating the Effectiveness of the Driving Resumption Assessment in Brain Disorders: Insights From a Retrospective Observational Study

Objectives For patients with brain disorders, regaining the ability to drive is crucial to their reintegration into society. Despite the existence of numerous assessment methods for determining the ability to resume driving, the most effective approach remains unclear. This study evaluated patients with brain disorders who had received support for driving resumption. We examined the factors influencing the acquisition of driving ability in this specific population. Methods This retrospective observational study was conducted from July 2019 to March 2022. Initially, a desk-based assessment was conducted using neuropsychological tests. Successful candidates subsequently underwent an on-road assessment at an affiliated driving school. Patients who passed both assessments were granted permission to resume driving. The participants were categorized into pass and fail groups based on their assessments, and a comparative analysis was conducted. Age, sex, type of brain disorder, functional independence measures (FIMs), assessments of higher cognitive skills, and physical function test results were evaluated. Results Forty-five patients (average age: 62±13 years) underwent evaluation. Logistic regression analysis for the desk-based assessment identified the Rey-Osterrieth complex figure test (ROCFT) (three-minute delayed recall) as the most influential factor (cutoff value: 21.5 points; sensitivity: 65%; specificity, 72.7%). In the on-road assessment, the 10-m walking test was significantly faster in the passing group than in the failing group (p<0.005). Conclusions We demonstrated that the ROCFT (three-minute delayed recall) was the most effective neuropsychological assessment tool for evaluating driving resumption. The assessment of walking speed may also be able to predict the resumption of driving in patients with brain disorders.

Nonmemory Composite Embedded Performance Validity Formulas in Patients with Multiple Sclerosis

OBJECTIVE

Research regarding performance validity tests (PVTs) in patients with multiple sclerosis (MS) is scant, with recommended batteries for neuropsychological evaluations in this population lacking suggestions to include PVTs. Moreover, limited work has examined embedded PVTs in this population. As previous investigations indicated that nonmemory-based embedded PVTs provide clinical utility in other populations, this study sought to determine if a logistic regression-derived PVT formula can be identified from selected nonmemory variables in a sample of patients with MS.

METHOD

A total of 184 patients (M age = 48.45; 76.6% female) with MS were referred for neuropsychological assessment at a large, Midwestern academic medical center. Patients were placed into "credible" (n = 146) or "noncredible" (n = 38) groups according to performance on standalone PVT. Missing data were imputed with HOTDECK.

RESULTS

Classification statistics for a variety of embedded PVTs were examined, with none appearing psychometrically appropriate in isolation (areas under the curve [AUCs] = .48-.64). Four exponentiated equations were created via logistic regression. Six, five, and three predictor equations yielded acceptable discriminability (AUC = .71-.74) with modest sensitivity (.34-.39) while maintaining good specificity (≥.90). The two predictor equation appeared unacceptable (AUC = .67).

CONCLUSIONS

Results suggest that multivariate combinations of embedded PVTs may provide some clinical utility while minimizing test burden in determining performance validity in patients with MS. Nonetheless, the authors recommend routine inclusion of several PVTs and utilization of comprehensive clinical judgment to maximize signal detection of noncredible performance and avoid incorrect conclusions. Clinical implications, limitations, and avenues for future research are discussed.

Untersuchung der Simulationssensibilität des Alertness-Tests der Testbatterie zur Aufmerksamkeitsprüfung (TAP)

Zur Sicherung valider Testprofile in der neuropsychologischen Begutachtung ist die Beurteilung der Plausibilität vorgebrachter Defizite unerlässlich. In der vorliegenden Studie wurde die Sensibilität für Täuschungsverhalten des Alertness-Tests der Testbatterie zur Aufmerksamkeitsprüfung (TAP) untersucht. Der Vergleich der Testleistungen von 17 Probanden unter (i) normaler Anstrengungsbereitschaft, (ii) Simulationsvorsatz und (iii) Simulation mit vorheriger Information über glaubhafte Täuschungsstrategien zeigte, dass informierte Probanden geringere Reaktionszeiten und Standardabweichungen als unter der naiven Simulationsbedingung aufweisen, aber weiterhin langsamere und inkonsistentere Reaktionen als unter optimaler Anstrengungsbereitschaft zeigen. Selbst unter willentlicher Anstrengung waren sie nicht fähig, normgerechte Standardabweichungen ihrer simulierten Minderleistung zu erreichen. Demnach deuten konstante Reaktionszeiten auf authentisches Leistungsverhalten hin. Im Vergleich zu Testdaten von Patienten zeigte sich, dass die Simulationsabsicht informierter Probanden mittels einzelner Testparameter nicht identifiziert werden kann. Unter Berücksichtigung mehrerer Testparameter ist es allerdings auch bei Kenntnis glaubhafter Täuschungsstrategien möglich, eine valide Beurteilung der Plausibilität der individuellen Leistung zu gewährleisten.

Test validity and performance validity: considerations in providing a framework for development of an ability-focused neuropsychological test battery

Literature on test validity and performance validity is reviewed to propose a framework for specification of an ability-focused battery (AFB). Factor analysis supports six domains of ability: first, verbal symbolic; secondly, visuoperceptual and visuospatial judgment and problem solving; thirdly, sensorimotor skills; fourthly, attention/working memory; fifthly, processing speed; finally, learning and memory (which can be divided into verbal and visual subdomains). The AFB should include at least three measures for each of the six domains, selected based on various criteria for validity including sensitivity to presence of disorder, sensitivity to severity of disorder, correlation with important activities of daily living, and containing embedded/derived measures of performance validity. Criterion groups should include moderate and severe traumatic brain injury, and Alzheimer's disease. Validation groups should also include patients with left and right hemisphere stroke, to determine measures sensitive to lateralized cognitive impairment and so that the moderating effects of auditory comprehension impairment and neglect can be analyzed on AFB measures.

Detection of Malingered Neurocognitive Dysfunction Among Patients with Acquired Brain Injuries

The Word Memory Test (WMT) is one of the most sensitive forced-choice tests available designed to evaluate negative response bias (NRB). Presently there is no valid verbal test designed to evaluate NRB for Hebrew-speaking patients. The aims of the present study were to validate the response bias measures of the WMT among Hebrew-speaking patients with acquired brain injuries and to reveal the malingering base rate among Israeli patients involved in compensation-seeking. Participants were 112 patients. The Test of Memory Malingering (TOMM) was used for convergent validity and injury related variables were used for concurrent validity. A translated version of the WMT had high split-half reliability. Regarding convergent validity, WMT effort measures had high positive correlations with the TOMM. Moreover, based on TOMM cutoff scores for classification, the WMT had reasonable classification rates. Regarding concurrent validity, multivariate logistic regression revealed that failure in the WMT was significantly predicted by normal brainscans and involvement in compensation-seeking behavior. The baserate of probable malingering was 34%. These findings emphasize the universality of the WMT in detecting NRB and establishing a malingered neurocognitive dysfunction baserate among Israeli patients involved in compensation-seeking.

Does the source of a forensic referral affect neuropsychological test performance on a standardized battery of tests?

The current study examines the differences in neuropsychological test performance between individuals who were referred for evaluation by either plaintiff or defense attorneys. Comparisons were made using a standardized battery of tests, with the same tests being administered to both groups of individuals along with the MMPI-2. The results of the study showed no significant difference in domain-level performance, or on the psychological measures administered for plaintiff vs defense referrals who passed symptom validity tests (SVTs). Similarly, although those failing SVTs produced markedly lower test performance and reported more psychological symptoms in comparison to those passing SVTs, there were no differences between plaintiff or defense referrals on test performance for those failing SVTs.

Test of Memory Malingering (TOMM) Scores are not Affected by Chronic Pain or Depression in Patients with Fibromyalgia

Neuropsychologists routinely give effort tests, such as the Test of Memory Malingering (TOMM). When a person fails one of these tests, the clinician must try to determine whether the poor performance was due to suboptimal effort or to chronic pain, depression, or other problems. Participants were 54 community-dwelling patients who met American College of Rheumatology criteria for fibromyalgia (FM). In addition to the TOMM, they completed the Beck Depression Inventory-Second Edition, Multidimensional Pain Inventory-Version 1, Oswestry Disability Index-2.0, British Columbia Cognitive Complaints Inventory, and the Fibromyalgia Impact Questionnaire. The majority endorsed at least mild levels of depressive symptoms (72%), and 22% endorsed "severe" levels of depression. The average scores on the TOMM were 48.8 (SD = 1.9, range = 40-50) for Trial 1, 49.8 (SD = 0.5, range = 48-50) for Trial 2, and 49.6 (SD = 0.9, range = 45-50) for Retention. Despite relatively high levels of self-reported depression, chronic pain, and disability, not a single patient failed the TOMM. In this study, the TOMM was not affected by chronic pain, depression, or both.

Suppressed Working Memory on the WMS-III as a Marker for Poor Effort

The purpose of this study was to examine the clinical utility of memory minus Working Memory Index (memory-WMI) discrepancy scores on the WMS-III for detecting poor effort in 145 personal injury litigants (19 poor effort, 126 adequate effort). On average, participants in the poor effort group performed significantly lower on all WMS-III memory indexes and demonstrated larger memory-WMI discrepancy scores compared to participants in the adequate effort group. Discriminant function analyses using memory-WMI discrepancy scores as independent variables revealed poor overall classification rates (60.0% to 63.4%). Based on the prevalence of unusually suppressed attention-concentration ability relative to memory functioning using unidirectional memory-WMI discrepancy scores, high specificity and negative predictive power values were found. However, there was unacceptably low sensitivity and positive predictive power. These results suggest that memory-WMI discrepancy scores on the WMS-III do not provide clinically useful information regarding response set and should be used cautiously as an indicator of poor effort.

Ecological Validity of the WMS-III Rarely Missed Index in Personal Injury Litigation

The purpose of this study was to evaluate the clinical utility of the Rarely Missed Index (RMI) to detect cognitive exaggeration in 78 nonlitigant patients (i.e., Mixed Clinical group) and 158 personal injury litigants (i.e., 20 Suspected Exaggerators, 12 Borderline Exaggerators, 126 Genuine Responders). The base rate for probable malingered neurocognitive dysfunction in the litigant sample was 12.7%. The false positive error rate of the RMI in the Genuine Responder and Mixed Clinical group ranged from 5.4% to 8.6%. Positive RMI scores were found in 25% and 41.7% of the Suspected Exaggerator and Borderline Exaggerator groups respectively. The clinical utility of the RMI to identify Suspected Exaggerators versus individuals in the Genuine Responder and Mixed Clinical groups revealed low sensitivity (sensitivity = .25), very high specificity (range = .91 to .95), moderate positive predictive power (range = .50 to .71), and moderate to high negative predictive power (range = .68 to .83). These results do not support the use of the RMI as a reliable predictor of cognitive exaggeration.

Validität und Reliabilität von Beschwerdenvalidierungstests und -indikatoren

Zusammenfassung: Beschwerdenvalidierungstests (BVT) dienen zur Überprüfung der Gültigkeit erhaltener Testprofile. Im Rahmen eines Analogdesigns wurden drei BVT (Medical Symptom Validity Test MSVT, Amsterdamer Kurzzeitgedächtnistest AKGT, One-in-Five Test) sowie eine Reihe von Beschwerdenvaliditätsindikatoren anderer Tests auf ihre Güte überprüft. 24 jüngere Erwachsene mit dem Mindestbildungsabschluss Abitur zeigten in der Untersuchung entweder ihre volle Leistung oder waren instruiert, entsprechend einem detaillierten Szenario überzeugend kognitive Störungen vorzutäuschen. Neben den drei BVT wurden folgende neuropsychologische Tests durchgeführt: der Trail Making Test (TMT), der Rey Complex Figure Test and Recognition Trial (RCFT), der Test d2, der Judgment of Line Orientation Test (JLO) und das Zahlennachsprechen des HAWIE-R, woraus auch die Reliable Digit Span (RDS) bestimmt wurde. Für den MSVT, den AKGT und die RDS konnten durch Testwiederholung nach zwei bis drei Tagen bzw. Einsatz einer Äquivalenzform des MSVT Reliabilitätsangaben erhalten werden. Für den AKGT und den MSVT-Durchgang Verzögerte Wiedererkennung ergaben sich zufrieden stellende Reliabilitätskoeffizienten (mit Phi-Koeffizienten von je 0.92), die für die RDS niedriger ausfielen (0.74). Die Ergebnisse zeigen auch eine gute Klassifikationsgüte für die BVT und die RDS, die zwischen 100 % (AKGT) und 79 % (One-in-Five Test) lag. Andere Validitätsindikatoren, die aus TMT, d2 und JLO ermittelt werden, schnitten schlechter ab. Während BVT gegenwärtig die best entwickelte Methodenklasse zur Diagnostik suboptimalen Leistungsverhaltens darstellen, sollte die Güte von Beschwerdenvaliditätsindikatoren, die aus Standardtests abgeleitet werden, deutlich besser überprüft werden, bevor ihr Einsatz in der Einzelfalldiagnostik in Frage kommt.

Assessment of malingering in chronic pain patients using neuropsychological tests

Validity checks into neuropsychological tests have been successful at detecting malingering in litigant patients with mild brain injury in recent years. This study expanded on these findings and examined whether 6 neuropsychological tests could be used to detect malingering in litigant (n = 55) and nonlitigant (n = 53) patients claiming cognitive deficits due to chronic pain. Encouraging findings were found. When patients were matched on age, gender, racial or ethnic background, years of education, and time postinjury, almost one third (29%) of patients in the litigant group failed 2 or more validity checks in these 6 neuropsychological tests versus none (0%) of the patients in the nonlitigant group. This result challenges the validity of some litigant patients who complain of cognitive deficits due to chronic pain. Furthermore, the findings suggest that neuropsychological assessments can be used as part of the assessment of chronic pain complainants. Further investigation of the validity markers in these 6 neuropsychological tests is recommended.