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The study examined the effect of preparation time and financial incentives on healthy adults' ability to simulate traumatic brain injury (TBI) during neuropsychological evaluation. A retrospective comparison of two TBI simulator group designs: a traditional design employing a single-session of standard coaching immediately before participation (SIM-SC; n = 46) and a novel design that provided financial incentive and preparation time (SIM-IP; n = 49). Both groups completed an ecologically valid neuropsychological test battery that included widely-used cognitive tests and five common performance validity tests (PVTs). Compared to SIM-SC, SIM-IP performed significantly worse and had higher rates of impairment on tests of processing speed and executive functioning (Trails A and B). SIM-IP were more likely than SIM-SC to avoid detection on one of the PVTs and performed somewhat better on three of the PVTs, but the effects were small and non-significant. SIM-IP did not demonstrate significantly higher rates of successful simulation (i.e., performing impaired on cognitive tests with <2 PVT failures). Overall, the rate of the successful simulation was ∼40% with a liberal criterion, requiring cognitive impairment defined as performance >1 SD below the normative mean. At a more rigorous criterion defining impairment (>1.5 SD below the normative mean), successful simulation approached 35%. Incentive and preparation time appear to add limited incremental effect over traditional, single-session coaching analog studies of TBI simulation. Moreover, these design modifications did not translate to meaningfully higher rates of successful simulation and avoidance of detection by PVTs. [ABSTRACT FROM AUTHOR]

The Delis-Kaplan Executive Function System (D-KEFS) Trail Making Test (TMT) is a commonly used measure of processing speed and executive functioning that may also be useful as an embedded performance validity test (PVT). We evaluated the utility of several multi-condition indices on the D-KEFS TMT in three independent samples to determine an optimal multi-condition index and cutoff on the D-KEFS TMT. Classification accuracy statistics for multiple multi-condition indices on the D-KEFS TMT were evaluated in three independent samples, including a sample with history of mild traumatic brain injury (TBI; n = 267) classified into psychometrically defined performance-valid and performance-invalid subgroups, the D-KEFS national normative sample (n = 1713), and a sample of middle- and older-aged adults diagnosed with mild cognitive impairment (MCI; n = 70). The D-KEFS TMT Conditions 1–5 summation index maximized sensitivity at.31 while maintaining adequate specificity at ≥.9. This index also had acceptable classification accuracy in both the D-KEFS national normative and MCI cross-validation samples, with the exception of the oldest subgroup of the national norming sample (i.e., individuals' ages 80–89), in which the observed failure rates for all multi-condition indices tested were greater than 10%. Our study provides support for the use the D-KEFS TMT Conditions 1–5 summation index as an embedded PVT among individuals younger than 80 years-old and from a range of conditions spanning from cognitively normal to mildly impaired; however, further validation is necessary. [ABSTRACT FROM AUTHOR]

While the Neuropsychological Assessment Battery, Screening Module (S-NAB) is a commonly used cognitive screening measure, no composite embedded performance validity test (PVT) formula has yet been described within it. This study sought to empirically derive PVT formulas within the S-NAB using an analog simulation paradigm. Seventy-two university students (M age = 18.92) were randomly assigned to either an Asymptomatic (AS) or simulated mild traumatic brain injury (S-mTBI) group and were administered a neuropsychological test battery that included the S-NAB and standalone and embedded PVTs. The AS group was instructed to perform optimally, and the S-mTBI group received symptom and test coaching to help simulate mTBI-related impairment. Both groups received warnings regarding the presence of PVTs throughout the test battery. Groups showed significant differences (all ps <.001) on all S-NAB domain scores and PVTs. In the S-NAB, the Attention (S-ATT) and Executive Function (S-EXE) domains showed the largest effect sizes (Cohen's ds = 2.02 and 1.79, respectively). Seven raw scores from S-ATT and S-EXE subtests were entered as predictor variables in a direct logistic regression (LR). The model accurately classified 90.3% of cases. Two PVT formulas were described: (1) an exponentiated equation from LR results and (2) an arithmetic formula using four individually meaningful variables. Both formulas demonstrated outstanding discriminability between groups (AUCs =.96–.97) and yielded good classification statistics compared to other PVTs. This study is the first to describe composite, embedded PVT formulas within the S-NAB. Implications, limitations, and appropriate future directions of inquiry are discussed. [ABSTRACT FROM AUTHOR]