title: Classification accuracy of the Portland digit recognition test in persons claiming exposure to environmental and industrial toxins.
abstract: The classification accuracy of the Portland digit recognition test (PDRT) in detecting cognitive malingering was studied in patients claiming cognitive deficits due to exposure to environmental or industrial toxins. Twenty-nine patients alleging toxic exposure and who met Slick et al. [Slick, D. J., Sherman, E. M. S., & Iverson, G. L. (1999). Diagnostic criteria for malingering neurocognitive dysfunction: Proposed standards for clinical practice and research. The Clinical Neuropsychologist, 13, 545-561] criteria for malingered neurocognitive dysfunction were compared to 14 toxic exposure patients negative for evidence of malingering. The published cutoffs were associated with a false positive error rate of 0% and sensitivity of more than 50%. When criterion for a PDRT failure was a positive PDRT finding on more than one section, the FP rate remained 0% while sensitivity improved to about 70%. The results indicate that a failed PDRT is an indication of malingering and not the neurological effect of a toxic substance or some other clinical phenomenon. The PDRT can be used with confidence as an indicator of negative response bias in cases of alleged exposure to neurotoxic substances.
authors.affiliation: Department of Psychology, University of New Orleans, New Orleans, LA, United States. kgreve@uno.edu
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Greve
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Bianchini
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Heinly
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Love
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Swift
authors.forename: Megan
authors.initials: M
authors.lastname: Ciota
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008306:Malingering / Q000145:classification / Q000175:diagnosis / Q000209:etiology; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D009784:Occupational Diseases / Q000139:chemically induced / Q000175:diagnosis*; D016273:Occupational Exposure / Q000009:adverse effects*; D012372:ROC Curve; D021641:Recognition, Psychology / Q000502:physiology*; D012680:Sensitivity and Specificity