Specificity of Embedded Performance Validity Tests in Elderly Veterans with Mild and Major Neurocognitive Disorder.

Abstract

This study explored the specificity of four embedded performance validity tests (PVTs) derived from common neuropsychological tasks in a sample of older veterans with verified cognitive decline and whose performance was deemed valid by licensed psychologists. Participants were 180 veterans who underwent comprehensive neuropsychological evaluation, were determined to have valid performance following profile analysis/conceptualization, and were diagnosed with mild neurocognitive disorder (i.e., MCI; n = 64) or major neurocognitive disorder (i.e., Dementia; n =116). All participants completed at least one of four embedded PVTs: Reliable Digit Span (RDS), California Verbal Learning Test-2nd ed. Short Form (CVLT-II SF) Forced choice, Trails B:A, and Delis-Kaplan Executive Function System (DKEFS) Letter and Category Fluency. Adequate specificity (i.e., ≥90%) was achieved at modified cut-scores for all embedded PVTs across MCI and Dementia groups. Trails B:A demonstrated near perfect specificity at its traditional cut-score (Trails B:A < 1.5). RDS ≤ 5 and CVLT-II SF Forced Choice ≤7 led to <10% false positive classification errors across MCI and dementia groups. DKEFS Letter and Category Fluency achieved 90% specificity at extremely low normative cut-scores. RDS, Trails B:A, and CVLT-II SF Forced Choice reflect promising embedded PVTs in the context of dementia evaluations. DKEFS Letter and Category Fluency appear too sensitive to genuine neurocognitive decline and, therefore, are inappropriate PVTs in adults with MCI or dementia. Additional research into embedded PVT sensitivity (via known-groups or analogue designs) in MCI and dementia is needed.