Factors contributing to performance validity test (PVT) and symptom validity test (SVT) performance in a Veteran TBI sample

Abstract:Objective: To examine the association between the validity cut scores of Neurobehavioral Symptom Inventory (NSI) (NIM5 >12, LOW6>13, Validity-10>22, NSI Total Score>58) and performance validity test (PVT) failure and to identify factors associated with both PVT and SVT failure in Veterans with traumatic brain injury (TBI). Participants and Methods: In this cross-sectional study, data from 277 participants who completed symptom validity tests (SVTs) on the NSI was collected. Mean age was 38.8 (SD=11.27) years, 88% were male, and 81.9% were White (87.0% Not Hispanic/Latino). Of these, a total of 60 participants had completed PVT testing. N=21 failed PVTs. The mean age of the PVT pass group was 46.08 (SD=13.44), 79.50% were male, and 82.05% were White (92.11% Not Hispanic/Latino). The mean age of the PVT fail group was 39.10 (SD=11.45), 90.48% were male, and 90.48% were White (90.48% Not Hispanic/Latino). Results: In examining the association between validity cut scores of the NSI and PVT failure, The NIM 5 validity scale was statistically significant (OR=21.00, 95% CI= 2.33, 188.54, p=0.006) meaning individuals the odds of failing PVTs were significantly higher among those who failed the NIM5 scale (NIM5>12, N=8) compared to those who passed the NIM5. Similarly, the odds of failing PVTs were higher amongst those who failed the Validity 10 (Validity-10>22, N=11) compared to those that passed the Validity 10 (OR=4.813, 95% CI= 1.19, 19.42, p=0.027), and the odds of failing PVTs were higher amongst those who failed the NSI overall (NSI>58) compared to those that passed the NSI (OR=21.00, 95% CI= 2.34, 188.54, p=0.006). After controlling for covariates, there was no relationship between NIM5 failure and PVT failure, all p>.05 in the presence of sex, anxiety, depression, chronic pain, headache, and history of substance use. The relationship between Validity 10 failure and PVT failure remained significant in the presence of depression (OR=4.70, p=.030) and substance use history (OR=5.31, p=0.21). Similarly, the association between NSI Total Score failure and PVT failure was significant after controlling for depression (OR=11.55, p<.001). In examining the effects of various predictors on PVT failure, the odds of failing PVT were lower among those were depressed when compared to those that were not (OR=0.199, 95% CI 0.047, 0.851, p=0.029). In examining the effects of various predictors on NSI failure, the odds of failing Validity-10 and NSI Total Score was higher in those that were depressed compared to those that were not (OR=5.44, 95% CI 1.166, 5.874, p=.020, OR=11.210, 95% CI 1.761, 8.707, p<.001, respectively). Conclusion: These findings provide valuable insights into the factors associated with PVT and SVT failure. Our study indicates depression as a significant factor associated with PVT and SVT failure, highlighting the need for comprehensive evaluation strategies in a Veteran population that consider a range of demographic, psychological, and medical factors to better understand and address performance validity and symptom validity testing issues.