Thirty-two studies of commonly researched neuropsychological malingering tests were meta-analytically reviewed to evaluate their effectiveness in discriminating between honest responders and dissimulators. Overall, studies using the Digit Memory Test (DMT), Portland Digit Recognition Test (PDRT), 15-Item Test, 21-Item Test, and the Dot Counting Test had average effect sizes indicating that dissimulators obtain scores that are approximately 1.1 standard deviations below those of honest responders. The DMT separated the means of groups of honest and dissimulating responders by approximately 2 standard deviations, whereas the 21-Item Test and the PDRT separated the groups by nearly 1.5 and 1.25 standard deviations, respectively. The 15-Item Test and the Dot Counting Test were less effective, separating group means by approximately 3/4 of a standard deviation. Although the DMT, PDRT, 15-, and 21-Item Tests all demonstrated very high specificity rates, at the level of individual classification, the DMT had the highest sensitivity and overall hit-rate parameters. The PDRT and 15-Item Test demonstrated moderate sensitivity, whereas the 21-Item Test demonstrated poor sensitivity. The less than perfect sensitivities of all the measures included in this review argue against their use in isolation as malingering screening devices.

The Timed Gait test is a standardized procedure assessing motor dysfunction of lower extremities and gait abnormalities associated with AIDS dementia complex. Heretofore, interpretations of Timed Gait results have been hampered by the lack of normative data. We provide results on this test derived from 1,549 subjects (HIV-seronegatives (HIV-) and seropositives (HIV+) classified according to ADC stage). Timed Gait was found to be a useful screening and assessment tool for evaluating ADC and correlated with clinical ADC staging as well as more extensive structured neurological and neuropsychological evaluations. Analysis of covariance results (with age and education as covariates) revealed symptomatic HIV+(SX) and AIDS groups having significantly slower Timed Gait scores than those in the HIV- and asymptomatic HIV+(ASX) groups. The SX group obtained significantly slower timed gait scores than those in the AIDS group. There was a significant increase in Timed Gait scores with each increase in dementia staging with the HIV- subjects having the fastest mean Timed Gait scores and the HIV+ dementia stage 2+ having the slowest. These normative data should prove useful in both recognition of ADC and treatment response. Given its minimal training requirements, the Timed Gait would have utility in resource limited settings.

The authors report on results from a new procedure for evaluating adequacy of effort given during neuropsychological testing. The letter memory test (LMT) is a computer-administered, 45-item, forced-choice recognition task that uses consonant letters as stimuli and manipulates face difficulty level along 2 dimensions: number of letters to be remembered and number of choices amongst which the target stimulus must be identified. In 3 studies that included either analogue or known groups designs, the LMT discriminated poorly motivated from well-motivated groups at a moderately high level of accuracy, which was comparable to that of the Digit Memory Test and superior to that of the 21-Item Test. The internal consistency reliability of the LMT was also high.Neuropsychological testing has developed primarily in medical settings where patient care is the main focus of attention. In

Few studies to date have cross-validated indicators of malingering that have been suggested on various neuropsychological tests. This study presents data cross-validating several indicators of malingering on neuropsychological tests, as well as on tests of malingering and via behavioral observations. It incorporates methodological recommendations by Rogers [Researching dissimulation. In: R. Rogers (Ed.), Clinical assessment of malingering and deception (pp. 309-327). New York: Guilford Press.] resulting in an ecologically valid design utilizing college students with a history of mild head injury as analog malingerers. Results indicated that the Letter Memory Test (LMT) and the Digit Memory Test (DMT) attained the highest hit rates for the detection of malingering, while the sensitivity of many other measures declined on cross-validation.

Thirty-two studies of commonly researched neuropsychological malingering tests were meta-analytically reviewed to evaluate their effectiveness in discriminating between honest responders and dissimulators. Overall, studies using the Digit Memory Test (DMT), Portland Digit Recognition Test (PDRT), 15-Item Test, 21-Item Test, and the Dot Counting Test had average effect sizes indicating that dissimulators obtain scores that are approximately 1.1 standard deviations below those of honest responders. The DMT separated the means of groups of honest and dissimulating responders by approximately 2 standard deviations, whereas the 21-Item Test and the PDRT separated the groups by nearly 1.5 and 1.25 standard deviations, respectively. The 15-Item Test and the Dot Counting Test were less effective, separating group means by approximately 3/4 of a standard deviation. Although the DMT, PDRT, 15-, and 21-Item Tests all demonstrated very high specificity rates, at the level of individual classification, the DMT had the highest sensitivity and overall hit-rate parameters. The PDRT and 15-Item Test demonstrated moderate sensitivity, whereas the 21-Item Test demonstrated poor sensitivity. The less than perfect sensitivities of all the measures included in this review argue against their use in isolation as malingering screening devices.