Differentiating poor validity from probable impairment on the medical symptom validity test: a cross-validation study.

AIMS: In neuropsychological evaluations, it is often difficult to ascertain whether poor performance on measures of validity is due to poor effort or malingering, or whether there is genuine cognitive impairment. Dunham and Denney created an algorithm to assess this question using the Medical Symptom Validity Test (MSVT). We assessed the ability of their algorithm to detect poor validity versus probable impairment, and concordance of failure on the MSVT with other freestanding tests of performance validity. METHODS: Two previously published datasets (n = 153 and n = 641, respectively) from outpatient neuropsychological evaluations were used to test Dunham and Denney's algorithm, and to assess concordance of failure rates with the Test of Memory Malingering and the forced choice measure of the California Verbal Learning Test, two commonly used performance validity tests. RESULTS: In both datasets, none of the four cutoff scores for failure on the MSVT (70%, 75%, 80%, or 85%) identified a poor validity group with proportionally aligned failure rates on other freestanding measures of performance validity. Additionally, the protocols with probable impairment did not differ from those with poor validity on cognitive measures. CONCLUSIONS: Despite what appeared to be a promising approach to evaluating failure on the easy MSVT subtests when clinical data are unavailable (as recommended in the advanced interpretation program, or advanced interpretation [AI], of the MSVT), the current findings indicate the AI remains the gold standard for doing so. Future research should build on this effort to address shortcomings in measures of effort in neuropsychological evaluations.

Substitution of California Verbal Learning Test, second edition for Verbal Paired Associates on the Wechsler Memory Scale, fourth edition.

Two common measures used to evaluate verbal learning and memory are the Verbal Paired Associates (VPA) subtest from the Wechsler Memory Scales (WMS) and the second edition of the California Verbal Learning Test (CVLT-II). For the fourth edition of the WMS, scores from the CVLT-II can be substituted for VPA; the present study sought to examine the validity of the substitution. For each substitution, paired-samples t tests were conducted between original VPA scaled scores and scaled scores obtained from the CVLT-II substitution to evaluate comparability. Similar comparisons were made at the index score level. At the index score level, substitution resulted in significantly lower scores for the AMI (p = .03; r = .13) but not for the IMI (p = .29) or DMI (p = .09). For the subtest scores, substituted scaled scores for VPA were not significantly different from original scores for the immediate recall condition (p = .20) but were significantly lower at delayed recall (p = .01). These findings offer partial support for the substitution. For both the immediate and delayed conditions, the substitution produced generally lower subtest scores compared to original VPA subtest scores.

Parsimonious estimation of the Wechsler Memory Scale, Fourth Edition demographically adjusted index scores: immediate and delayed memory.

The recent release of the Wechsler Memory Scale Fourth Edition contains many improvements from a theoretical and administration perspective, including demographic corrections using the Advanced Clinical Solutions. Although the administration time has been reduced from previous versions, a shortened version may be desirable in certain situations given practical time limitations in clinical practice. The current study evaluated two- and three-subtest estimations of demographically corrected Immediate and Delayed Memory index scores using both simple arithmetic prorating and regression models. All estimated values were significantly associated with observed index scores. Use of Lin's Concordance Correlation Coefficient as a measure of agreement showed a high degree of precision and virtually zero bias in the models, although the regression models showed a stronger association than prorated models. Regression-based models proved to be more accurate than prorated estimates with less dispersion around observed values, particularly when using three subtest regression models. Overall, the present research shows strong support for estimating demographically corrected index scores on the WMS-IV in clinical practice with an adequate performance using arithmetically prorated models and a stronger performance using regression models to predict index scores.

Parsimonious prediction of Wechsler Memory Scale, Fourth Edition scores: immediate and delayed memory indexes.

Research on previous versions of the Wechsler Memory Scale (WMS) found that index scores could be predicted using a parsimonious selection of subtests (e.g., Axelrod & Woodard, 2000). The release of the Fourth Edition (WMS-IV) requires a reassessment of these predictive formulas as well as the use of indices from the California Verbal Learning Test-II (CVLT-II). Complete WMS-IV and CVLT-II data were obtained from 295 individuals. Six regression models were fit using WMS-IV subtest scaled scores-Logical Memory (LM), Visual Reproduction (VR), and Verbal Paired Associates (VPA)-and CVLT-II substituted scores to predict Immediate Memory Index (IMI) and Delayed Memory Index (DMI) scores. All three predictions of IMI significantly correlated with the complete IMI (r = .92 to .97). Likewise, predicted DMI scores significantly correlated with complete DMI (r = .92 to .97). Statistical preference was indicated for the models using LM, VR, and VPA, in which 97% and 96% of the cases fell within two standard errors of measurement (SEMs) of full index scores, respectively. The present findings demonstrate that the IMI and DMI can be reliably estimated using two or three subtests from the WMS-IV, with preference for using three. In addition, evidence suggests little to no improvement in predictive accuracy with the inclusion of CVLT-II indices.

[image omitted] Derivation of a composite measure of embedded symptom validity indices.

Assessment of effort on cognitive testing has become a suggested standard in both forensic and clinical neuropsychological assessment. Both stand-alone and empirically derived embedded measures have been developed, however guidelines for combining several measures are not always available. This study used logistic regression analysis to derive a multivariable composite to detect suboptimal effort using scores extracted from commonly administered neuropsychological tests. A model predicting suboptimal effort, as defined by performance on the Medical Symptom Validity Test, was created with 124 participants using variables from the California Verbal Learning test 2nd edition, Rey Complex Figure Test and the Wechsler Memory Scale 3rd edition. The model reliably predicted suboptimal effort (χ(2 )= 44.37, p < .001) with excellent discrimination (AUC = .84).

Concurrent validity of three forced-choice measures of symptom validity.

Forced-choice measures of recognition memory are used to assess the validity of an evaluation by using cutoff scores that discriminate individuals demonstrating good effort from those who are intentionally performing suboptimally. The current study evaluated three measures of motivation in a clinical sample of over 150 individuals. The Forced-Choice subtest from the California Verbal Learning Test and the Test of Memory Malingering generated comparable percentages of poor effort at 23% and 21%, respectively, yet they did not have complete concordance. Overall detection of poor performance using the 85% cut score on the three easy subtests from the Medical Symptom Validity Test (MSVT; Green, 2004) fell at 37%. When the MSVT cut score was lowered to 70%, the failure rate dropped to 21%, consistent with the other two measures and embedded measures of effort. The data are discussed in terms of adjusting the MSVT cut score and examining comparability in detection rates across these measures of symptom validity.

The utility of the post-concussive symptom questionnaire.

The Post-concussive Symptom Questionnaire (PCSQ) and its short forms were evaluated to determine their utility in measuring symptom validity as brief self-report measures in 112 individuals referred for a neuropsychological evaluation. First, the relationships between the PCSQ forms and measures of cognitive performance (Wechsler Adult Intelligence Scale-Fourth Edition Full-Scale IQ, California Verbal Learning Test-Second Edition Trials 1-5 Total T-score, Trails B, FAS), general distress (Minnesota Multiphasic Personality Inventory [MMPI]-2 M8), and self-report symptom validity (MMPI-2 FBS Symptom Validity Scale [FBS] and Response Bias Scale [RBS]) were investigated to determine construct validity. Measures of self-report symptom validity explained the greatest amount of variance. Second, receiver operating characteristics curve analyses were conducted to determine the predictive value of the PCSQ forms in detecting over reporting on the FBS and the RBS in addition to establishing optimal cutoff scores. On the basis of the proposed cutoff scores, sensitivity, specificity, positive predictive power, negative predictive power, and hit rates were calculated.

Impact of the presence of alcohol at the time of injury on acute and one-year cognitive and functional recovery after traumatic brain injury.

The presence of alcohol is clearly a risk factor for sustaining a traumatic brain injury (TBI); however, the impact of alcohol on injury severity, and functional or cognitive outcome is unclear, as there is mixed evidence in the literature. This study examined 482 participants in a large urban medical center with documented mild-complicated to severe TBI and blood alcohol testing for functional and cognitive outcome. Functional outcomes were measured by the Functional Independence Measure (FIM) and cognitive outcomes were measured using neuropsychological tests known to be sensitive to the sequelae of TBI. Consistent with the hypotheses, there was a statistically significant negative impact of alcohol intoxication at the time of injury on Glasgow Coma Scale (GCS); however intoxication only lowered GCS by an average of 1.9 points. There was a statistically significant relationship between blood alcohol levels (BAL) and FIM at the time of admission to inpatient rehabilitation, but BAL accounted for only 3% of the variance in FIM total score. There was no relationship between BAL and FIM at discharge from rehabilitation or at 1-year follow-up. There was no statistically significant relationship between BAL at the time of injury and cognitive functioning at 1-year follow-up; however, contrary to the hypotheses GCS failed to show a strong relationship with cognitive outcome.

Analysis of the dementia profile on the Medical Symptom Validity Test.

The Medical Symptom Validity Test (MSVT) was administered as part of a neuropsychological battery to a mixed clinical sample of 286 consecutively referred individuals. Of the 47% of the sample who failed in the easy subtests, 48% were considered to have the "dementia profile." The remaining 52% of individuals failing the easy subtests were considered by the task to have "poor effort." Comparing the neuropsychological test performance among these three groups (Pass, Dementia Profile, Poor Effort) found that on most tasks those individuals passing the easy subtests of the MSVT perform significantly better than the other two groups, which did not differ from each other. Individuals meeting criteria for the Dementia Profile performed worse on tasks of motor functioning and list learning in comparison to the Poor Effort group. The results suggest that the algorithm creating a Dementia Profile does not effectively differentiate groups of individuals who fail the easy subtests of the MSVT. Consideration of a more liberal cutoff score for the easy subtests is offered.

Test-retest reliability of the Traumatic Brain Injury Screening Instrument.

The Traumatic Brain Injury Screening Instrument (TBISI) was implemented in Veterans Affairs medical facilities in an attempt to identify Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF) veterans with possible mild TBI. Despite its widespread implementation, the reliability and validity of the screening tool has not yet been established. The current study reports preliminary findings on the test-retest reliability of the TBISI in 44 OEF/OIF veterans referred for neuropsychological evaluation following a positive TBI screen. Results suggest overall poor test-retest reliability of the TBI screening tool with regard to type of event, injuries sustained, and resulting sequelae. These findings underscore the importance of further investigation of its psychometric properties to promote accurate identification and referral of veterans with possible TBI.

Improved prenatal aneuploidy screening using the novel advanced first-trimester screening algorithm: a multicenter study of 10,017 pregnancies.

PURPOSE: : It has been postulated that the maternal age component should be completely excluded from first-trimester screening (FTS) for fetal aneuploidies. In this study, we tested a new algorithm known as advanced first-trimester screening (AFS), which disregards maternal age. METHOD: : In a multicenter study, FTS findings were retrieved from 10,017 pregnancies. FTS risk assessment was performed using the Nicolaides method, and the AFS score was calculated. The results of both methods were compared. RESULTS: : Within this population, 81 fetuses had an abnormal karyotype. The sensitivity of the 2 algorithms was 86.4%. When the AFS method was used, the positive predictive value rose from 9.6% (FTS) to 12.4% (AFS). Using AFS, the test positive rate could be decreased by 161 cases (-22.2%) (p < 0.0001), due to a reduction of false positive cases. As a result, the false positive rate of AFS was 24.5% lower than that of FTS, while the same number of aneuploidies was detected. CONCLUSION: : AFS can markedly reduce the rate of false positive test results. If these results are confirmed by larger multicenter studies, the new AFS will represent a great improvement in fetal aneuploidy screening. (c) 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.

The relationship between visual contrast sensitivity and neuropsychological performance in a healthy elderly sample.

Visual acuity and contrast sensitivity are two visual domains affected by normal aging; however, the potential impact of well-documented changes in these abilities on neuropsychological assessment is relatively unstudied. The current study examined the relationship between these abilities and neuropsychological performance in a healthy, community-based elderly sample. Fifty-one individuals (Age: M = 79.6) were assessed for visual acuity and visual contrast sensitivity, and received a brief neuropsychological battery. Results indicated contrast sensitivity was significantly related to neuropsychological performance on visually based measures, but not auditory measures. Visual acuity was only weakly related to neuropsychological performance. Clinical implications for assessment of elderly individuals are discussed.

Hemispheric interaction and consciousness: degree of handedness predicts the intensity of a sensory illusion.

It has been suggested that the two cerebral hemispheres play different roles in the maintenance and updating of an individual's beliefs. In particular it has been suggested that the left hemisphere (LH) forms consistent beliefs, whereas the right hemisphere (RH) monitors for inconsistencies or anomalies in reference to these beliefs. If some threshold of inconsistencies is detected, the role of the RH is to update the LH's belief system accordingly. Handedness may reflect the degree to which the two hemispheres exchange information such that the more strongly handed an individual is, the less interhemispheric communication may take place, thus attenuating this updating process. Two studies were carried out that confronted participants with conflicting, anomalous sensory information by tapping on both the participant's real hand and a fake hand in synchrony. One conclusion would be to update the LH belief system to include the fake hand as their own and consciously experience the taps as coming from the fake hand. It was predicted that this experience would vary with handedness such that the more strongly handed a participant was, the less they would experience the sensory illusion. Study 1 supported this, with more strongly handed participants reporting lesser degrees of the illusion. A second study replicated this effect and included a variable that measured the time it took for a participant to experience the illusion. A non-significant trend was present such that more strongly handed participants were slower to experience the illusion. Last, although the illusion was felt equally in both the left and right hand conditions, correlations between handedness and the illusion were only present in the left hand condition. A model of how interhemispheric interaction may function in maintaining beliefs and consciousness is presented.