Cognitive "success" in the setting of performance validity test failure

BACKGROUND

Although studies have shown unique variance contributions from performance invalidity, it is difficult to interpret the meaning of cognitive data in the setting of performance validity test (PVT) failure. The current study aimed to examine cognitive outcomes in this context.

METHOD

Two hundred and twenty-two veterans with a history of mild traumatic brain injury referred for clinical evaluation completed cognitive and performance validity measures. Standardized scores were characterized as Within Normal Limits (≥16th normative percentile) and Below Normal Limits (<16th percentile). Cognitive outcomes are examined across four commonly used PVTs. Self-reported employment and student status were used as indicators of "productivity" to assess potential functional differences related to lower cognitive performance.

RESULTS

Among participants who performed in the invalid range on Test of Memory Malingering trial 1, Word Memory Test, Wechsler Adult Intelligence Scale-Fourth Edition Digit Span aged corrected scaled score, and the California Verbal Learning Test-Second Edition Forced Choice index, 16-88% earned broadly within normal limits scores across cognitive testing. Depending on which PVT measure was applied, the average number of cognitive performances below the 16th percentile ranged from 5 to 7 of 14 tasks. There were no differences in the total number of below normal limits performances on cognitive measures between "productive" and "non-productive" participants (T = 1.65, p = 1.00).

CONCLUSIONS

Results of the current study suggest that the range of within normal limits cognitive performance in the context of failed PVTs varies greatly. Importantly, our findings indicate that neurocognitive data may still provide important practical information regarding cognitive abilities, despite poor PVT outcomes. Further, given that rates of below normal limits cognitive performance did not differ among "productivity" groups, results have important implications for functional abilities and recommendations in a clinical setting.

Development and application of novel performance validity metrics for computerized neurocognitive batteries

OBJECTIVES

Data from neurocognitive assessments may not be accurate in the context of factors impacting validity, such as disengagement, unmotivated responding, or intentional underperformance. Performance validity tests (PVTs) were developed to address these phenomena and assess underperformance on neurocognitive tests. However, PVTs can be burdensome, rely on cutoff scores that reduce information, do not examine potential variations in task engagement across a battery, and are typically not well-suited to acquisition of large cognitive datasets. Here we describe the development of novel performance validity measures that could address some of these limitations by leveraging psychometric concepts using data embedded within the Penn Computerized Neurocognitive Battery (PennCNB).

METHODS

We first developed these validity measures using simulations of invalid response patterns with parameters drawn from real data. Next, we examined their application in two large, independent samples: 1) children and adolescents from the Philadelphia Neurodevelopmental Cohort (n = 9498); and 2) adult servicemembers from the Marine Resiliency Study-II (n = 1444).

RESULTS

Our performance validity metrics detected patterns of invalid responding in simulated data, even at subtle levels. Furthermore, a combination of these metrics significantly predicted previously established validity rules for these tests in both developmental and adult datasets. Moreover, most clinical diagnostic groups did not show reduced validity estimates.

CONCLUSIONS

These results provide proof-of-concept evidence for multivariate, data-driven performance validity metrics. These metrics offer a novel method for determining the performance validity for individual neurocognitive tests that is scalable, applicable across different tests, less burdensome, and dimensional. However, more research is needed into their application.

Adaptation and initial validation of the Arabic version of the Word Memory Test (WMTARB)

BACKGROUND

The feigning of cognitive impairment is common in neuropsychological assessments, especially in a medicolegal setting. The Word Memory Test (WMT) is a forced-choice recognition memory performance validity test (PVT) which is widely used to detect noncredible performance. Though translated to several languages, this was not done for one of the most common languages, Arabic. The aim of the current study was to evaluate the convergent validity of the Arabic adaptation of the WMT (WMT_ARB) among Israeli Arabic speakers.

METHODS

We adapted the WMT to Arabic using the back-translation method and in accordance with relevant guidelines. We then randomly assigned healthy Arabic speaking adults (N = 63) to either a simulation or honest control condition. The participants then performed neuropsychological tests which included the WMT_ARB and the Test of Memory Malingering (TOMM), a well-validated nonverbal PVT.

RESULTS

The WMT_ARB had high split-half reliability and its measures were significantly correlated with that of the TOMM (p < .001). High concordance was found in classification of participants using the WMT_ARB and TOMM (specificity = 94.29% and sensitivity = 100% using the conventional TOMM trial 2 cutoff as gold standard). As expected, simulators' accuracy on the WMT_ARB was significantly lower than that of honest controls. None of the demographic variables significantly correlated with WMT_ARB measures.

CONCLUSION

The WMT_ARB shows initial evidence of reliability and validity, emphasizing its potential use in the large population of Arabic speakers and universality in detecting noncredible performance. The findings, however, are preliminary and mandate validation in clinical settings.

Examining the Clinical Utility of Selected Memory-Based Embedded Performance Validity Tests in Neuropsychological Assessment of Patients with Multiple Sclerosis

Within the neuropsychological assessment, clinicians are responsible for ensuring the validity of obtained cognitive data. As such, increased attention is being paid to performance validity in patients with multiple sclerosis (pwMS). Experts have proposed batteries of neuropsychological tests for use in this population, though none contain recommendations for standalone performance validity tests (PVTs). The California Verbal Learning Test, Second Edition (CVLT-II) and Brief Visuospatial Memory Test, Revised (BVMT-R)—both of which are included in the aforementioned recommended neuropsychological batteries—include previously validated embedded PVTs (which offer some advantages, including expedience and reduced costs), with no prior work exploring their utility in pwMS. The purpose of the present study was to determine the potential clinical utility of embedded PVTs to detect the signal of non-credibility as operationally defined by below criterion standalone PVT performance. One hundred thirty-three (133) patients (M age = 48.28; 76.7% women; 85.0% White) with MS were referred for neuropsychological assessment at a large, Midwestern academic medical center. Patients were placed into “credible” (n = 100) or “noncredible” (n = 33) groups based on a standalone PVT criterion. Classification statistics for four CVLT-II and BVMT-R PVTs of interest in isolation were poor (AUCs = 0.58–0.62). Several arithmetic and logistic regression-derived multivariate formulas were calculated, all of which similarly demonstrated poor discriminability (AUCs = 0.61–0.64). Although embedded PVTs may arguably maximize efficiency and minimize test burden in pwMS, common ones in the CVLT-II and BVMT-R may not be psychometrically appropriate, sufficiently sensitive, nor substitutable for standalone PVTs in this population. Clinical neuropsychologists who evaluate such patients are encouraged to include standalone PVTs in their assessment batteries to ensure that clinical care conclusions drawn from neuropsychological data are valid.

Evidence for Cognitive Decline in Chronic Pain: A Systematic Review and Meta-Analysis

Background: People with chronic pain (CP) sometimes report impaired cognitive function, including a deficit of attention, memory, executive planning, and information processing. However, the association between CP and cognitive decline was still not clear. Our study aimed to assess the association of CP as a risk factor with cognitive decline among adults. Methods: We included data from clinical studies. Publications were identified using a systematic search strategy from PubMed, Embase, and Cochrane Library databases from inception to October 10, 2020. We used the mean cognitive outcome data and the standard deviations from each group. The standardized mean difference (SMD) or odds ratio (OR), and 95% confidence intervals (CI) were performed for each cognitive decline outcome. I 2-values were assessed to quantify the heterogeneities. Results: We included 37 studies with a total of 52,373 patients with CP and 80,434 healthy control participants. Because these studies used different evaluative methods, we analyzed these studies. The results showed CP was associated with cognitive decline when the short-form 36 health survey questionnaire (SF-36) mental component summary (SMD = -1.50, 95% CI = -2.19 to -0.81), the Montreal cognitive assessment (SMD = -1.11, 95% CI = -1.60 to -0.61), performance validity testing (SMD = 3.05, 95% CI = 1.74 to 4.37), or operation span (SMD = -1.83, 95% CI = -2.98 to -0.68) were used. However, we got opposite results when the studies using International Classification of Diseases and Related Health Problems classification (OR = 1.58, 95% CI = 0.97 to 2.56), the Mini-Mental State Examination (SMD = -0.42, 95% CI = -0.94 to 0.10; OR = 1.14, 95% CI = 0.91 to 1.42), and Repeatable Battery for the Assessment of Neuropsychological Status memory component (SMD = -0.06, 95% CI = -0.37 to 0.25). Conclusion: There may be an association between CP and the incidence of cognitive decline when some cognitive, evaluative methods were used, such as short-form 36 health survey questionnaire, Montreal cognitive assessment, performance validity testing, and operation span.

Considerations regarding noncredible performance in the neuropsychological assessment of patients with multiple sclerosis: A case series

Determining the validity of data during clinical neuropsychological assessment is crucial for proper interpretation, and extensive literature has emphasized myriad methods of doing so in diverse samples. However, little research has considered noncredible presentation in persons with multiple sclerosis (pwMS). PwMS often experience one or more factors known to impact validity of data, including major neurocognitive impairment, psychological distress/psychogenic interference, and secondary gain. This case series aimed to illustrate the potential relationships between these factors and performance validity testing in pwMS. Six cases from an IRB-approved database containing pwMS referred for neuropsychological assessment at a large, academic medical center involving at least one of the above-stated factors were identified. Backgrounds, neuropsychological test data, and clinical considerations for each were reviewed. Interestingly, no pwMS diagnosed with major neurocognitive impairment was found to have noncredible performance, nor was any patient with noncredible performance in the absence of notable psychological distress. Given the variability of noncredible performance and multiplicity of factors affecting performance validity in pwMS, clinicians are strongly encouraged to consider psychometrically appropriate methods for evaluating validity of cognitive data in pwMS. Additional research aiming to elucidate base rates of, mechanisms begetting, and methods for assessing noncredible performance in pwMS is imperative.

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.

Normal cognitive test scores cannot be interpreted as accurate measures of ability in the context of failed performance validity testing: A symptom- and detection-coached simulation study

Introduction: While use of performance validity tests (PVTs) has become a standard of practice in neuropsychology, there are differing opinions regarding whether to interpret cognitive test data when standard scores fall within normal limits despite PVTs being failed. This study is the first to empirically determine whether normal cognitive test scores underrepresent functioning when PVTs are failed.Method: Participants, randomly assigned to either a simulated malingering group (n = 50) instructed to mildly suppress test performances or a best-effort/control group (n = 50), completed neuropsychological tests which included the North American Adult Reading Test (NAART), California Verbal Learning Test - 2^nd Edition (CVLT-II), and Test of Memory Malingering (TOMM).Results: Groups were not significantly different in age, sex, education, or NAART predicted intellectual ability, but simulators performed significantly worse than controls on the TOMM, CVLT-II Forced Choice Recognition, and CVLT-II Short Delay Free Recall. The groups did not significantly differ on other examined CVLT-II measures. Of simulators who failed validity testing, 36% scored no worse than average and 73% scored no worse than low average on any of the examined CVLT-II indices.Conclusions: Of simulated malingerers who failed validity testing, nearly three-fourths were able to produce cognitive test scores that were within normal limits, which indicates that normal cognitive performances cannot be interpreted as accurately reflecting an individual's capabilities when obtained in the presence of validity test failure. At the same time, only 2 of 50 simulators were successful in passing validity testing while scoring within an impaired range on cognitive testing. This latter finding indicates that successfully feigning cognitive deficits is difficult when PVTs are utilized within the examination.

Valid or not: A critique of Graver and Green

Disagreements in science and medicine are not uncommon, and formal exchanges of disagreements serve a variety of valuable roles. As identified by a Nature Methods editorial entitled "The Power of Disagreement" (2016), disagreements bring attention to best practices so that differences in interpretation do not result from inferior data sets or confirmation bias, "prompting researchers to take a second look at evidence that is not in agreement with their hypothesis, rather than dismiss it as artifacts." Graver and Green published reasons why they disagree with a recent clinical case report and a decades old randomized control trial characterizing the effect of an acute 2 mg dosing of lorazepam on the Word Memory Test. In this article, we formally responded to their commentary to further clarify the reasons for our data interpretations. These two opposing views provide an excellent learning opportunity, particularly for students, demonstrating the importance of careful articulation of the rationale behind certain conclusions from different perspectives. We encourage careful review of the original articles being discussed so the neuropsychologists can read both positions and decide which interpretation of the findings they consider most sound.