Practice effects predict cognitive outcome in amnestic mild cognitive impairment (original) (raw)
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Practice effects predict cognitive outcome in amnestic Mild Cognitive Impairment NIH Public Access
Objective—Practice effects on cognitive tests have been shown to further characterize patients with amnestic Mild Cognitive Impairment (aMCI), and may provide predictive information about cognitive change across time. We tested the hypothesis that a loss of practice effects would portend a worse prognosis in aMCI. Design—Longitudinal, observational design following participants across one year. Setting—Community-based cohort. Participants—Three groups of older adults: 1. cognitively intact (n=57), 2. aMCI with large practice effects across one week (MCI+PE, n=25), and 3. aMCI with minimal practice effects across one week (MCI−PE, n=26). Measurements—Neuropsychological tests. Results—After controlling for age and baseline cognitive differences, the MCI−PE group performed significantly worse than the other groups after one year on measures of immediate memory, delayed memory, language, and overall cognition. Conclusions—Although these results need to be replicated in larger samples, the loss of short-term practice effects portends a worse prognosis in patients with aMCI. Keywords Mild Cognitive Impairment; practice effects; dementia Practice effects are improvements in cognitive test performance after repeated exposure to the same test materials. Such improvements have traditionally been viewed as sources of error (1). Although practice effects are robust in cognitively intact older adults (1,2) and largely absent in patients with dementia (3,4), evidence is equivocal about practice effects in
Lower practice effects as a marker of cognitive performance and dementia risk: A literature review
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring, 2020
Background: Practice effects (PEs) are improvements in performance after repeated exposure to test materials, and typically viewed as a source of bias in repeated cognitive assessments. We aimed to determine whether characterizing PEs could also provide a useful marker of early cognitive decline. Methods: We conducted a systematic review of the literature, searching PsycInfo (Ebsco) and PubMed databases for articles studying PEs in aging and dementia populations. Articles published between 1920 and 2019 were included. Result: We identified 259 articles, of which 27 studied PEs as markers of cognitive performance. These studies consistently showed that smaller, less-robust PEs were associated with current diagnostic status and/or future cognitive decline. In addition, lower PEs were associated with Alzheimer's disease risk factors and neurodegeneration biomarkers. Conclusion: PEs provide a potentially useful marker of cognitive decline, and could prove valuable as part of a cost-effective strategy to select individuals who are at-risk for dementia for future interventions.
Frontiers in Psychology
Objectives: To identify learning effects and meaningful changes in amnestic mild cognitive impairment (aMCI) at a follow-up assessment. Method: The Spanish version of the California Verbal Learning Test (CVLT) was administered to a sample of 274 adults of age over 50 years with subjective memory complains (SMC), including single and multiple domain aMCI groups and participants with SMC but without cognitive impairment (SMC group). The Wilcoxon test was used to compare results at baseline and after 18 months in short and long recall, and standardized regression-based (SRB) methods were used to study meaningful changes. Results: Scores were significantly higher at follow-up for short and long-delayed recall in all groups indicating generalized practice effect. SRB scores indicated a significant decline in recall in a higher proportion of participants with aMCI than in SMC group. Discussion: Patients with multiple and single domain aMCI benefit from practice in a verbal learning memory test. The SRB approach revealed a higher incidence of meaningful decline in short and long-delay recall and recognition in the aMCI groups than in the SMC group. Specifically, compared to SMC participants, single-domain aMCI individuals declined in a higher proportion in all measures, and multiple-domain aMCI individuals in long delay free recall.
Underdiagnosis of mild cognitive impairment: A consequence of ignoring practice effects
Alzheimer's & dementia (Amsterdam, Netherlands), 2018
Longitudinal testing is necessary to accurately measure cognitive change. However, repeated testing is susceptible to practice effects, which may obscure true cognitive decline and delay detection of mild cognitive impairment (MCI). We retested 995 late-middle-aged men in a ∼6-year follow-up of the Vietnam Era Twin Study of Aging. In addition, 170 age-matched replacements were tested for the first time at study wave 2. Group differences were used to calculate practice effects after controlling for attrition effects. MCI diagnoses were generated from practice-adjusted scores. There were significant practice effects on most cognitive domains. Conversion to MCI doubled after correcting for practice effects, from 4.5% to 9%. Importantly, practice effects were present although there were declines in uncorrected scores. Accounting for practice effects is critical to early detection of MCI. Declines, when lower than expected, can still indicate practice effects. Replacement participants ar...
Archives of Clinical Neuropsychology, 2007
Practice effects, defined as improvements in cognitive test performance due to repeated exposure to the test materials, have traditionally been viewed as sources of error. However, they might provide useful information for predicting cognitive outcome. The current study used three separate patient samples (older adults with mild cognitive impairments, individuals who were HIV +, individuals with Huntington's disease) to examine the relationship between practice effects and cognitive functioning at a later point. Across all three samples, practice effects accounted for as much as 31 to 83% of the variance in the follow-up cognitive scores, after controlling for baseline cognitive functioning. If these findings can be replicated in other patients with neurodegenerative disorders, clinicians and researchers may be able to develop predictive models to identify the individuals who are most likely to demonstrate continued cognitive decline across time. The ability to utilize practice effects data would add a simple, convenient, and non-invasive marker for monitoring an individual patient's cognitive status. Additionally, this prognostic index could be used to offer interventions to patients who are in the earliest stages of progressive neurodegenerative disorders.
Alzheimer's & dementia : the journal of the Alzheimer's Association, 2016
This study investigated the validity of two brief cognitive tests (Memory Alteration Test [M@T] and Test Your Memory [TYM] test) for identifying people with aMCI in the community. Older people were invited to participate by their general practitioner practice. Eligible participants were assessed for aMCI using an operationalized approach to the Petersen criteria and the M@T and TYM. Both tests demonstrated significant ability in discriminating between people with aMCI and controls (AUC = 0.91 for M@T and 0.80 for TYM [P < .001 for both]). M@T performed with higher sensitivity than TYM (85% vs. 63%) and similar specificity (84% vs. 87%). Both tests demonstrated moderate test-retest reliability (κ = ∼0.5) and took <10 minutes to administer. M@T and TYM are quick to administer. M@T demonstrated higher diagnostic test accuracy than TYM and could provide an efficient method for identifying aMCI in clinical and research settings.
Persistence of Neuropsychological Testing Deficits in Mild Cognitive Impairment
Dementia and Geriatric Cognitive Disorders, 2009
Background: The significant variability across studies of mild cognitive impairment (MCI) in rates of progression to Alzheimer’s disease (AD) and reversion to normal cognition may be due to differences in specific neuropsychological tests and thresholds used to define MCI. Methods: We assessed 115 subjects with amnestic (AMN) or non-amnestic (NON) MCI on a standardized neuropsychological battery at baseline and after a mean follow-up of 16.4 months to determine the prevalence and persistence of deficits identified with specific tests. Results: The prevalence of impaired performance varied widely across tests. Deficits were more persistent in the AMN group than in the NON group. Baseline deficits in Visual Reproduction II and the California Verbal Learning Test were the best predictors of persistent memory impairment. Subjects who at baseline were impaired on multiple memory tests or had poorer overall memory performance were more likely to exhibit persistent memory deficits. Conclus...
Within-Session Practice Effects in Patients Referred for Suspected Dementia
Dementia and Geriatric Cognitive Disorders, 2012
Practice effects are improvements in cognitive test performance associated with repeated administrations of same or similar measures and are traditionally seen as error variance. However, there is growing evidence that practice effects provide clinically useful information. Methods: Within-session practice effects (WISPE) across 2 h were collected from 61 non-consecutive patients referred for suspected dementia and compared to the Mini Mental Status Examination (MMSE), a screening measure of dementia severity. Results: In all patients, WISPE on two cognitive measures were significantly correlated with MMSE, even after controlling for baseline cognitive scores (partial r = 0.47, p < 0.001; partial r = 0.26, p = 0.046). In patients diagnosed with probable Alzheimer's disease, the trend was even stronger (partial r = 0.72, p < 0.01; partial r = 0.58, p = 0.046). In both groups, lower WISPE were associated with lower MMSE scores (i.e. greater dementia severity), even after controlling for initial cognitive scores. Conclusion: If future research validates these findings with longitudinal studies, then WISPE may have important clinical applications in dementia evaluations.