The Word Memory Test in medicolegal assessment: a measure of effort and malingering?

ABSTRACT

The Word Memory Test (WMT) is claimed to measure effort and to detect cognitive response bias. Archival data from n = 2526 cases referred in 2009–2016 for medicolegal assessment were analyzed. Each participant underwent a medical and a psychological examination including a cognitive test battery and several validity measures including the WMT. The WMT validity test scores do not approximately follow a normal distribution. Thus, parametric statistics for WMT validity scores may not be appropriate. WMT performance explains 0–20% of the variance in cognitive test performance. This is more than what substantial brain damage accounts for. The standard uniform cutoff indicating a ‘fail’ in all three WMT effort subtests (equal or less than 82.5% correct responses) seems not supported by the data. Taking into account the context of the testing, cutoffs may be chosen according to the desired sensitivity or specificity. ROC-statistics with modified Slick criteria as gold standard for malingering look alike for the three WMT effort subtests, with a AUC between 0.86 and 0.88. The WMT seems a good indicator of both effort and (Slick) malingering, however, little is gained by administering the entire test.

KEYWORDS:

• Medicolegal assessment
• performance validity
• psychological testing
• WMT
• Slick criteria

Disclosure statement

No potential conflict of interest was reported by the authors.