Practice Effect of Repeated Cognitive Tests Among Older Adults: Associations With Brain Amyloid Pathology and Other Influencing Factors

Abstract

BackgroundPractice effects (PE), after repeated cognitive measurements, may mask cognitive decline and represent a challenge in clinical and research settings. However, an attenuated practice effect may indicate the presence of brain pathologies. This study aimed to evaluate practice effects on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) scale, and their associations with brain amyloid status and other factors in a cohort of cognitively unimpaired older adults enrolled in the CHARIOT-PRO SubStudy.Materials and Methods502 cognitively unimpaired participants aged 60-85 years were assessed with RBANS in both screening and baseline clinic visits using alternate versions (median time gap of 3.5 months). We tested PE based on differences between test and retest scores in total scale and domain-specific indices. Multiple linear regressions were used to examine factors influencing PE, after adjusting for age, sex, education level, APOE-ε4 carriage and initial RBANS score. The latter and PE were also evaluated as predictors for amyloid positivity status based on defined thresholds, using logistic regression.ResultsParticipants’ total scale, immediate memory and delayed memory indices were significantly higher in the second test than in the initial test (Cohen’s dz = 0.48, 0.70 and 0.35, P < 0.001). On the immediate memory index, the PE was significantly lower in the amyloid positive group than the amyloid negative group (P = 0.022). Older participants (≥70 years), women, non-APOE-ε4 carriers, and those with worse initial RBANS test performance had larger PE. No associations were found between brain MRI parameters and PE. In addition, attenuated practice effects in immediate or delayed memory index were independent predictors for amyloid positivity (P < 0.05).ConclusionSignificant practice effects on RBANS total scale and memory indices were identified in cognitively unimpaired older adults. The association with amyloid status suggests that practice effects are not simply a source of measurement error but may be informative with regard to underlying neuropathology.

Computerized cognitive practice effects in relation to amyloid and tau in preclinical Alzheimer's disease: Results from a multi‐site cohort

“…27 Interestingly, we also show a C3 practice effect of approximately ¼ of a standard deviation, a magnitude that is consistent with other cognitive tests, patient samples, retest intervals, and demographic variables. 5,6,28 The lack of amyloid association with practice effects contributes to the larger mixed literature that has shown both diminished practice effects (predominantly examined using the same test versions) associated with higher levels of amyloid 10,[29][30][31] as well as no significant relationship. 4,[31][32][33] Importantly, with our additional assessment of tau, we show that although practice effects are not related to amyloid status, diminished practice effects are significantly related to tau burden in the MTL, IT, and IP among A+ CUs when initial performance is considered.…”

“…While the literature on how C3 performance, specifically, is impacted by AD biomarkers is small, reduced practice effects on other neuropsychological tests have been shown to reflect underlying AD neuropathology (for review, see 13 ). For example, domain‐specific practice effects on the Repeatable Battery for the Assessment of Neuropsychological Status memory subscales only were identified in CU older adults and were reduced in the A+ group 10 . Reduced practice effects have even been identified in A− CU older adults who are APOE e4 carriers, highlighting the utility of practice effects for early detection 17 …”

“… 4 Practice effects, or expected improved performance on repeated testing reflecting learning, 5 , 6 can easily be quantified from repeat testing over short intervals on computerized assessments. Diminished practice effects have been associated with future cognitive decline, 7 , 8 , 9 amyloid status, 10 , 11 and neurodegeneration biomarkers including CSF amyloid and tau 12 across the AD spectrum. 13 Importantly, practice effects can be due to conceptual‐ and form‐related familiarity as individuals gain experience with both general task procedures and specific test stimuli if the same test versions are used, or conceptual‐related familiarity alone if alternate stimuli are used.…”

“…For example, domain-specific practice effects on the Repeatable Battery for the Assessment of Neuropsychological Status memory subscales only were identified in CU older adults and were reduced in the A+ group. 10 Reduced practice effects have even been identified in A− CU older adults who are APOE e4 carriers, highlighting the utility of practice effects for early detection. 17 The goal of the present study was to extend our understanding of cross-sectional performance and practice effects on the C3 in a large-scale multi-site study of preclinical AD.…”

Video Teleconference Administration of the Addenbrooke’s Cognitive Examination-III for the Assessment of Neuropsychological Status: An Experience in Indian Subjects with Cognitive Dysfunction

“…Zheng et al . [ 18 ] used alternate versions of RBANS in 502 cognitively unimpaired participants, aged 60-85 years, at a median gap of 3.5 months. Participants’ total scale, immediate memory, and delayed memory indices were significantly higher in the second test (Cohen’s d z = 0.48, 0.70, and 0.35, P < 0.001) as compared to the baseline.…”