Time and money: Exploring enhancements to performance validity research designs

Abstract

Introduction

The study examined the effect of preparation time and financial incentives on healthy adults’ ability to simulate traumatic brain injury (TBI) during neuropsychological evaluation.

Method

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).

Results

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%.

Conclusions

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.

Keywords:

• Malingering
• performance validity
• traumatic brain injury

Acknowledgments

We thank Carole Koviak and Robert Kotasek of the Southeastern Michigan Traumatic Brain Injury Model System; Shoshana Krohner, Barret Vermilion, and Monica De Iorio for their invaluable help and support in data collection.

Disclosure statement

The authors report no conflict of interest.

Additional information

Funding

This research was supported by grants from the National Institute on Disability, Independent Living and Rehabilitation Research (NIDILRR; Rapport, 90IFOO92; Hanks, 90DPTB0006) and Wayne State University Graduate School Thesis and Dissertation grants (Kanser, Bashem).