Empirically derived algorithm for performance validity assessment embedded in a widely used neuropsychological battery: Validation among TBI patients in litigation

Introduction: Validity of neuropsychological assessment depends, inter alia, on the cooperation of the examinee, requiring separate assessment. Stand-alone tests devised for detecting negative response bias (NRB) are exposed to potential threats to their validity. In this study, an algorithm was developed for assessing NRB within a standardized, computerized neuropsychological battery (NeuroTrax), making it difficult to detect and circumvent. Method: Data were collected from the archived medical records of 75 outpatients with mild to moderate head injury, all in litigation. Participants were classified as low or high likelihood for NRB, using a known test for effort assessment (Test of Memory Malingering). Results: Variables judged to be prone for exaggeration and showing large differences between the groups were entered into a logistic regression analysis. The resulting formula exhibited high specificity (98.0%) and sensitivity (87.5%), classifying correctly 94% of the cases. Conclusion: It is suggested that the algorithm developed empirically using scores on the NeuroTrax computerized battery can be a useful tool for assessing effort. This algorithm should resist threats to its validity and can be automatically computed while assessing a range of cognitive skills.