Predictors of Retest Effects in a Longitudinal Study of Cognitive Aging in a Diverse Community-Based Sample

Abstract

OBJECTIVE Better performance due to repeated testing can bias long-term trajectories of cognitive aging and correlates of change. We examined whether retest effects differ as a function of individual differences pertinent to cognitive aging: race/ethnicity, age, sex, language, years of education, and dementia risk factors including APOE ε4 status, baseline cognitive performance, and cardiovascular risk. METHOD We used data from the Washington Heights-Inwood Columbia Aging Project, a community-based cohort of older adults (n=4,073). We modeled cognitive change and retest effects in summary factors for general cognitive performance, memory, executive functioning, and language using multilevel models. Retest effects were parameterized in two ways, as improvement between the first and subsequent testings, and as the square root of the number of prior testings. We evaluated whether the retest effect differed by individual characteristics. RESULTS The mean retest effect for general cognitive performance was 0.60 standard deviations (95%CI: 0.46, 0.74), and was similar for memory, executive functioning, and language. Retest effects were greater for participants in the lowest quartile of cognitive performance, consistent with regression to the mean. Retest did not differ by other characteristics. CONCLUSIONS Retest effects are large in this community-based sample, but do not vary by demographic or dementia-related characteristics. Differential retest effects may not limit the generalizability of inferences across different groups in longitudinal research.

Modeling practice effects in healthy middle‐aged participants of the Alzheimer and Families parent cohort

“…Age did not significantly predict any discrepancy score in univariate regressions, whereas education showed an effect only in visual puzzles discrepancy score. This globally negative findings match those previous studies that reported no relevant influences of age and education on PE [13–15,37]. However, it is worth mention that our results could be substantially driven by the narrow age range and the homogeneous middle‐upper education of the studied sample.…”

“…In a thorough meta‐analysis, Calamia et al. reported a consistent negative effect of age in PE [12], although some studies have not observed such relationship [13–15]. Although less studied, the level of formal education has also shown disagreeing results.…”

Change in Cognitive Performance From Midlife Into Old Age: Findings from the Midlife in the United States (MIDUS) Study

“…Our comparison of the longitudinal and the refresher samples provided a way to examine retest effects (Gross et al, 2015)). The results suggest there were no significant retest effects, consistent with other studies with intervals greater than seven years (Salthouse, Schroeder, & Ferrer, 2004).…”

Relationship Between Type 2 Diabetes Mellitus and Cognitive Change in a Multiethnic Elderly Cohort

“…Given that individuals with diabetes mellitus had significantly less education than those without, it is possible that they had less experience with test taking and strategies for maximizing test performance. These individuals may have the most to gain from practicing the cognitive tests, although a recent study demonstrated that retest effects do not differ according to vascular risk burden in the WHICAP sample . Also, there is potential selection bias due to attrition related to diabetes mellitus morbidity and mortality.…”