Embedded Effort Indicators on the California Verbal Learning Test – Second Edition (CVLT–II): An Attempted Cross-Validation

Abstract

This study determined whether the logistic regression method that was recently developed by Wolfe and colleagues (2010) for the detection of invalid effort on the California Verbal Learning Test – Second Edition (CVLT–II) could be cross-validated in an independent sample of 100 consecutively referred patients with traumatic brain injury. Although the CVLT–II logistic regression formula demonstrated a statistically significant level of agreement with results from the Word Memory Test, it was associated with an unacceptably high proportion of false positives. The component variables of the logistic regression were sensitive to length of coma but did not covary with psychosocial complicating factors (e.g., unresolved prior psychiatric history) that were associated with a higher relative risk of failure of WMT validity criteria. It is concluded that the Wolfe et al. logistic regression should be used only with great caution in the context of clinical neuropsychological evaluations.

Keywords:

• Effort
• assessment
• validity
• California Verbal Learning Test – Second edition
• CVLT–II

Acknowledgments

The authors thank Dr. Scott Millis for his helpful comments on some of the preliminary statistical analyses. However, the conclusions and opinions expressed in this paper are exclusively those of the authors.