The relationship between performance validity testing, external incentives, and cognitive functioning in long COVID.

Introduction: Performance validity test (PVT) failures occur in clinical practice and at higher rates with external incentives. However, little PVT research has been applied to the Long COVID population. This study aims to address this gap.

Methods: Participants were 247 consecutive individuals with Long COVID seen for neuropsychological evaluation who completed 4 PVTs and a standardized neuropsychological battery. The sample was 84.2% White and 66% female. The mean age was 51.16 years and mean education was 14.75 years. Medical records were searched for external incentive (e.g., disability claims). Three groups were created based on PVT failures (Pass [no failures], Intermediate [1 failure], and Fail [2+ failures]).

Results: A total of 8.9% participants failed 2+ PVTs, 6.4% failed one PVT, and 85% passed PVTs. From the full sample, 25.1% were identified with external incentive. However, there was a significant difference between the rates of external incentives in the Fail group (54.5%) compared to the Pass (22.1%) and Intermediate (20%) groups. Further, the Fail group had lower cognitive scores and higher frequency of impaired range scores, consistent with PVT research in other populations. External incentives were uncorrelated with cognitive performance.

Conclusions: Consistent with other populations, results suggest Long COVID cases are not immune to PVT failure and external incentives are associated with PVT failure. Results indicated that individuals in the Pass and Intermediate groups showed no evidence for significant cognitive deficits, but the Fail group had significantly poorer cognitive performance. Thus, PVTs should be routinely administered in Long COVID cases and research.