ACSS yielded better classification accuracy and sensitivity/specificity than RDS and RDS-R. While all three indices have utility as embedded PVTs, ACSS ≤ 5 may be most robust to cognitive impairment while identifying noncredible performance.
To supplement memory-based Performance Validity Tests (PVTs) in identifying noncredible performance, we examined the validity of the two most commonly used nonmemory-based PVTs—Dot Counting Test (DCT) and Wechsler Adult Intelligence Scale–Fourth edition (WAIS-IV) Reliable Digit Span (RDS)—as well as two alternative WAIS-IV Digit Span (DS) subtest PVTs. Examinees completed DCT, WAIS-IV DS, and the following criterion PVTs: Test of Memory Malingering, Word Memory Test, and Word Choice Test. Validity groups were determined by passing 3 (valid; n = 69) or failing ⩾2 (noncredible; n = 30) criterion PVTs. DCT, RDS, RDS–Revised (RDS-R), and WAIS-IV DS Age-Corrected Scaled Score (ACSS) were significantly correlated (but uncorrelated with memory-based PVTs). Combining RDS, RDS-R, and ACSS with DCT improved classification accuracy (particularly for DCT/ACSS) for detecting noncredible performance among valid-unimpaired, but largely not valid-impaired examinees. Combining DCT with ACSS may uniquely assess and best supplement memory-based PVTs to identify noncredible neuropsychological test performance in cognitively unimpaired examinees.
Objective
An increasing focus in Alzheimer’s disease and aging research is to identify transitional cognitive decline. One means of indexing change over time in serial cognitive evaluations is to calculate standardized regression-based (SRB) change indices. This paper includes the development and preliminary validation of SRB indices for the Uniform Data Set 3.0 Neuropsychological Battery, as well as base rate data to aid in their interpretation.
Method
The sample included 1,341 cognitively intact older adults with serial assessments over 0.5–2 years in the National Alzheimer’s Coordinating Center Database. SRB change scores were calculated in half of the sample and then validated in the other half of the sample. Base rates of SRB decline were evaluated at z-score cut-points, corresponding to two-tailed p-values of .20 (z = −1.282), .10 (z = −1.645), and .05 (z = −1.96). We examined convergent associations of SRB indices for each cognitive measure with each other as well as concurrent associations of SRB indices with clinical dementia rating sum of box scores (CDR-SB).
Results
SRB equations were able to significantly predict the selected cognitive variables. The base rate of at least one significant SRB decline across the entire battery ranged from 26.70% to 58.10%. SRB indices for cognitive measures demonstrated theoretically expected significant positive associations with each other. Additionally, CDR-SB impairment was associated with an increasing number of significantly declined test scores.
Conclusions
This paper provides preliminary validation of SRB indices in a large sample, and we present a user-friendly tool for calculating SRB values.
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