Utility of CVLT–3 response bias as a measure of performance validity after traumatic brain injury

Abstract

Objective

We sought to determine the utility of a new performance validity index that was recently proposed. In particular, we wanted to determine if this index would be associated with a specificity of at least .90, a sensitivity of at least .40, and an Area Under the Curve of at least .70 in a traumatic brain injury (TBI) sample.

Method

We used logistic regression to investigate how well this new index could distinguish persons with TBI (n = 148) who were evaluated within 1–36 months after injury. All participants had been classified on the basis of at least two independent performance validity tests as having provided valid performance (n = 128) or invalid performance (n = 20).

Results

The new performance validity index had acceptable specificity (.96) but had suboptimal sensitivity (.35) and Area Under the Curve (.66). It was concerning that almost half (5/12) of the cases that were identified by this index as providing invalid effort were false positives. Although a slightly more liberal cut-off improved sensitivity, the problem with poor positive predictive power remained. The conventional Forced Choice index had relatively better classification accuracy.

Conclusion

Differences in base rates between the original sample of Martin et al. and the current one most likely affected positive predictive power of the new index. Although their performance validity has excellent specificity, the current results do not support the application of this index in the clinical evaluation of patients with traumatic brain injury when base rates of invalid performance differ markedly from those in the original study.

Keywords:

• Assessment
• performance validity
• specificity

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

The author(s) reported there is no funding associated with the work featured in this article.