Suppressed working memory on the WMS-III as a marker for poor effort.
The purpose of this study was to examine the clinical utility of memory minus Working Memory Index (memory-WMI) discrepancy scores on the WMS-III for detecting poor effort in 145 personal injury litigants (19 poor effort, 126 adequate effort). On average, participants in the poor effort group performed significantly lower on all WMS-III memory indexes and demonstrated larger memory-WMI discrepancy scores compared to participants in the adequate effort group. Discriminant function analyses using memory-WMI discrepancy scores as independent variables revealed poor overall classification rates (60.0% to 63.4%). Based on the prevalence of unusually suppressed attention-concentration ability relative to memory functioning using unidirectional memory-WMI discrepancy scores, high specificity and negative predictive power values were found. However, there was unacceptably low sensitivity and positive predictive power. These results suggest that memory-WMI discrepancy scores on the WMS-III do not provide clinically useful information regarding response set and should be used cautiously as an indicator of poor effort.
Lange
Rael T
RT
Riverview Hospital, Coquitlam, British Columbia, Canada. rlange@bcmhs.bc.ca
Iverson
Grant L
GL
Sullivan
Karen
K
Anderson
Debbie
D
D000328:Adult; D001288:Attention / Q000502:physiology*; D005260:Female; D006801:Humans; D007603:Jurisprudence; D008297:Male; D008306:Malingering / Q000175:diagnosis / Q000503:physiopathology; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009449:Neurocirculatory Asthenia / Q000175:diagnosis* / Q000503:physiopathology*; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D014888:Wechsler Scales / Q000706:statistics & numerical data*; D014894:Weights and Measures