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Updated: Jul 16, 2025

Randomized, Triple-Blind, and Parallel-Controlled Trial of Transcranial Direct Current Stimulation for Cognitive Rehabilitation after Stroke
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Ascertainment and Statistical Issues for Randomized Trials of Cardiovascular Interventions for Cognitive Impairment

Nicholas M Pajewski1, Michael C Donohue2, Rema Raman2

  • 1Department of Biostatistics and Data Science (N.M.P., M.A.E.), Wake Forest University School of Medicine, Winston-Salem, NC.

Hypertension (Dallas, Tex. : 1979)
|September 21, 2023
PubMed

Insights

Improving cardiovascular risk factors may slow cognitive decline. However, randomized trials face design challenges in measuring dementia prevention, requiring large studies with long follow-up.

Area of Science:

  • Cardiovascular disease research
  • Neurology
  • Gerontology

Background:

  • Cardiovascular disease prevention has advanced significantly, reducing morbidity and mortality.
  • Emerging evidence suggests cardiovascular risk factor management may also impact cognitive decline and dementia.
  • The SPRINT trial highlighted potential links between cardiovascular health and cognitive function.

Purpose of the Study:

  • To review the design and analytic obstacles of randomized trials in assessing cognitive decline and dementia prevention.
  • To discuss the selection of appropriate cognitive endpoints for future preventive trials.
  • To identify key considerations for designing effective trials in this area.

Main Methods:

  • Review of randomized trial methodologies, specifically referencing the SPRINT trial.
  • Analysis of challenges in applying traditional cardiovascular trial designs to cognitive endpoints.
  • Discussion of various cognitive endpoint options, including neuropsychological tests, adjudicated impairment, and biomarkers.

Main Results:

  • Standard randomized trial designs face significant obstacles when applied to cognitive decline and dementia.
  • Selecting appropriate cognitive endpoints involves complex statistical and clinical considerations.
  • Challenges include statistical power, ascertainment methods, clinical relevance, interval censoring, missing data, competing risks, and practice effects.

Conclusions:

  • Future trials investigating the cardiovascular contribution to cognitive decline require careful endpoint selection.
  • These trials necessitate large sample sizes, diverse age groups, and extended follow-up periods.
  • Ethical considerations, such as equipoise, are also crucial in trial design.

Keywords:
biomarkerscognitioncognitive dysfunctiondementia

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