Publication date: Sep 13, 2025
Objective: Cognitive intraindividual variability (IIV) dispersion measures within-person variability in performance across a neuropsychological test battery and is prognostic of structural and functional decline. Although evidence for the construct validity of cognitive dispersion has grown considerably, its utility in applied settings relies on its stability and reliability. Thus, we examined mean-level stability, test-retest reliability, and reliable change of several cognitive dispersion indices among cognitively unimpaired older adults. Method: Participants were 2224 robustly cognitively unimpaired older adults from the National Alzheimer’s Coordinating Center (NACC) Uniform Data Set 3. 0. Intraindividual standard deviation (ISD) and coefficient of variation (CoV) dispersion indices were calculated for raw, scaled, and demographically-adjusted normed scores for the neuropsychological test battery at baseline and initial follow-up visit (M = 424. 99). Analyses included paired samples t-tests and generation of effect sizes for mean-level stability, correlations for test-retest reliability, and practice-adjusted reliable change indices (RCIs) for classifying individuals. Results: The mean-level change effect sizes for ISD and CoV scores were very small (ds
| Concepts | Keywords |
|---|---|
| 99days | cognitive aging |
| Alzheimer | cognitive dispersion |
| Literature | Intraindividual variability |
| Neuropsychological | neuropsychological assessment |
| Reliable | psychometrics |
Semantics
| Type | Source | Name |
|---|---|---|
| disease | IDO | process |