Detection of Inadequate Effort on Neuropsychological Testing A Meta-Analytic Review of Selected Procedures

Abstract

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.

New measures to detect malingered neurocognitive deficit: Applying reaction time and event-related potentials

“…Vickery et al (2001) published a meta-analysis of widely studied malingering tests and found that most had large effect sizes, high specificity (percentage of honest patients correctly classified) and moderate sensitivity (percentage of feigners correctly classified). However, recently, concerns have been raised that unscrupulous parties to legal proceedings may be "coaching" plaintiffs to avoid being detected by commonly used malingering tests TOMM;Tombaugh, 1996), other approaches have explored aspects of the evaluee's responses that are under less conscious control, such as reaction time (RT) and brain activity using electroencephalograph (EEG).…”

The New Gold Standard

“…Lest they be unnecessarily neglected in favor of more sophisticated measures, Boone and Lu state that cross-validation data justify the ongoing use of non-forced-choice measures. In Chapter 4, Grote and Hook remind us that effect sizes of forcedchoice tasks generally trump those of non-forced-choice procedures (Vickery et al, 2001). Grote and Hook reiterate that intentionality, the sine qua non of malingering, is difficult to operationalize.…”

Use of MMPI-2 to predict cognitive effort: A hierarchically optimal classification tree analysis

“…For instance, the "90% rule" (i.e., raw score cutoffs that are less than 90% correct on forcedchoice measures) is a commonly suggested "rule of thumb" and raises the possibility of IE (e.g., Grote et al, 2000). A previous meta-analysis (Vickery et al, 2001) found the Digit Memory Test (DMT; Hiscock & Hiscock, 1989) to be most effective in identifying IE relative to other effort measures examined, including non-forced-choice measures. Similar forced-choice measures, such as the Victoria Symptom Validity Test (VSVT; Slick et al, 1995), the Test of Memory Malingering (TOMM; Tombaugh, 1996), Multi-Digit Memory Test (MDMT; Niccolls & Bolter, 1991), Word Memory Test (WMT; Green, 2003), and the Letter Memory Test (LMT; Inman et al, 1998) have also demonstrated respective utility in civil and simulating samples.…”

“…This approach entails a priori identification of symptom exaggeration unrelated to the MMPI-2 (e.g., sufficient vs. insufficient cognitive effort performance), and MMPI-2 profiles or effort performances of over-reporting groups themselves or relative to groups shown to have not exaggerated symptoms are then observed Optimal CTA and cognitive effort 843 (e.g., Boone & Lu, 1999;Ross et al, 2004). Response validity meta-analyses have also been conducted (e.g., Nelson et al, 2006;Rogers et al, 1994Rogers et al, , 2003Vickery et al, 2001), which may provide the clinician with a variety of potential moderators to consider, such as gender, criminal versus civil litigation context, and type of clinical population examined (e.g., traumatic brain injury, chronic pain, etc.). Differently, classification tree analysis (CTA) with univariable optimal data analysis (ODA; Yarnold & Soltysik, 2005) is another approach that may be particularly beneficial to the clinician's everyday practice in the examination of psychological versus cognitive response validity data.…”