Cognitive impairment does not cause invalid performance: analyzing performance patterns among cognitively unimpaired, impaired, and noncredible participants across six performance validity tests

Abstract

Objective: Performance validity tests (PVTs) are essential in neuropsychological evaluations; however, it has been questioned how PVTs function in the context of cognitive impairment, and whether cognitive impairment alone is sufficient to cause PVT failure. Further, there is concern that some clinicians will disregard failed PVTs due to their perception that failures represent false-positive errors secondary to cognitive impairment. This study examined patterns associated with cognitively impaired versus noncredible performance across a battery of PVTs and neuropsychological tests. Additionally, the impact of VA service-connection and disability-seeking status on test validity was investigated.Method: A mixed-clinical sample of 103 veterans were administered six PVTs and neuropsychological tests. Performance was compared across three groups: valid-cognitively unimpaired, valid-cognitively impaired, and noncredible.Results: Significant PVT score differences and failure rates emerged across the three groups, with nonsignificant to small differences between valid-unimpaired and valid-impaired groups, and large differences between impaired and noncredible groups. In contrast, there were nonsignificant to small differences on neuropsychological tests between the valid-impaired and noncredible groups, indicating that impaired participants performed significantly better on PVTs despite comparable neurocognitive test scores. Service-connection rating itself was not associated with PVT failure, but an active disability claim to increase and/or establish service connection was associated with worse PVT performance.Conclusion: This study supports the use of multiple PVTs during evaluations of patients with varied cognitive abilities. Results indicated increased risk of PVT failure in patients who were seeking initiation/increase in service-connected payments, and shows that cognitive impairment does not cause PVT failure.