ArticleAlzheimer's & dementia (New York, N. Y.)2017
Potential implications of practice effects in Alzheimer's disease prevention trials.
Article in Alzheimer's & dementia (New York, N. Y.), 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 21 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
21 citing papers in PubMed, 23 citations in OpenAlex.
- Trial
- Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) Trial: Genetic Resource for Precision Nutrition.Nutrients · 2025Trial
- Cognitive and Neuropsychiatric Effects of 40 Hz tACS Simultaneously with Cognitive Exercises for Dementia: A Randomized, Crossover, Double-Blind, Sham-Controlled Study.Medicina (Kaunas, Lithuania) · 2025Trial
- Brain responses to intermittent fasting and the healthy living diet in older adults.Cell metabolism · 2024Trial
- Trial of the MIND Diet for Prevention of Cognitive Decline in Older Persons.The New England journal of medicine · 2023Trial
- A Clinical Trial of Transcranial Electromagnetic Treatment in Alzheimer's Disease: Cognitive Enhancement and Associated Changes in Cerebrospinal Fluid, Blood, and Brain Imaging.Journal of Alzheimer's disease : JAD · 2019Trial
- Treatment of Clinically Diagnosed Alzheimer's Disease by External Counterpulsation A Randomized Clinical Trial.American journal of Alzheimer's disease and other dementiasTrial
- Effects of Prior Exercise Habits and Adherence on Cognitive Function, Physical Fitness, and Vascular Health in Older Adults: An Exploratory Exercise-Based Intervention Trial.Dementia and neurocognitive disorders · 2026Article
- Practice effects persist over two decades of cognitive testing: Implications for longitudinal research.medRxiv : the preprint server for health sciences · 2025Article
- A Closer Look at Practice Effects in Mild Cognitive Impairment and Alzheimer's Disease.Archives of clinical neuropsychology : the official journal of the National Academy of Neuropsychologists · 2024Observational
- Short-Term Practice Effects on Cognitive Tests Across the Late Life Cognitive Spectrum and How They Compare to Biomarkers of Alzheimer's Disease.Journal of Alzheimer's disease : JAD · 2024Article
- Optimal Weighting of Preclinical Alzheimer's Cognitive Composite (PACC) Scales to Improve their Performance as Outcome Measures for Alzheimer's Disease Clinical Trials.International journal of statistics in medical research · 2023Article
- Why a clinical trial is as good as its outcome measure: A framework for the selection and use of cognitive outcome measures for clinical trials of Alzheimer's disease.Alzheimer's & dementia : the journal of the Alzheimer's Association · 2023Article
- LASSI-L detects early cognitive changes in pre-motor manifest Huntington's disease: a replication and validation study.Frontiers in neurology · 2023Article
- Testing the amyloid cascade hypothesis: Prevention trials in autosomal dominant Alzheimer disease.Alzheimer's & dementia : the journal of the Alzheimer's Association · 2022Article
- Avoid or Embrace? Practice Effects in Alzheimer's Disease Prevention Trials.Frontiers in aging neuroscience · 2022Article
- Practice effects in cognitive assessments three years later in non-carriers but not in symptom-free mutation carriers of autosomal-dominant Alzheimer's disease: Exemplifying procedural learning and memory?Frontiers in aging neuroscience · 2022Article
- Neurostimulation for cognitive enhancement in Alzheimer's disease (the NICE-AD study): a randomized clinical trial.Neurodegenerative disease management · 2021Article
- Cognitive composites in AD trials? Drinking the Kool-Aid and paying the price?Alzheimer's & dementia (Amsterdam, Netherlands) · 2020Article
- State, trait, and accumulated features of the Alzheimer's Disease Assessment Scale Cognitive Subscale (ADAS-Cog) in mild Alzheimer's disease.Alzheimer's & dementia (New York, N. Y.)Article
Corrections and comments
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Authors and funding
6 authors at 2 institutions in 1 country.
Funding
Abstract
introductionPractice effects (PEs) present a potential confound in clinical trials with cognitive outcomes. A single-blind placebo run-in design, with repeated cognitive outcome assessments before randomization to treatment, can minimize effects of practice on trial outcome.
methodsWe investigated the potential implications of PEs in Alzheimer's disease prevention trials using placebo arm data from the Alzheimer's Disease Cooperative Study donepezil/vitamin E trial in mild cognitive impairment. Frequent ADAS-Cog measurements early in the trial allowed us to compare two competing trial designs: a 19-month trial with randomization after initial assessment, versus a 15-month trial with a 4-month single-blind placebo run-in and randomization after the second administration of the ADAS-Cog. Standard power calculations assuming a mixed-model repeated-measure analysis plan were used to calculate sample size requirements for a hypothetical future trial designed to detect a 50% slowing of cognitive decline.
resultsOn average, ADAS-Cog 13 scores improved at first follow-up, consistent with a PE and progressively worsened thereafter. The observed change for a 19-month trial (1.18 points) was substantively smaller than that for a 15-month trial with 4-month run-in (1.79 points). To detect a 50% slowing in progression under the standard design (i.e., a 0.59 point slowing), a future trial would require 3.4 times more subjects than would be required to detect the comparable percent slowing (i.e., 0.90 points) with the run-in design. DISCUSSION: Assuming the improvement at first follow-up observed in this trial represents PEs, the rate of change from the second assessment forward is a more accurate representation of symptom progression in this population and is the appropriate reference point for describing treatment effects characterized as percent slowing of symptom progression; failure to accommodate this leads to an oversized clinical trial. We conclude that PEs are an important potential consideration when planning future trials.
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.