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Clinical Trials

Clinical Trials

Clinical trials are prospective experimental studies conducted on humans to determine the safety and efficacy of treatments, drugs, diet methods, and medical devices. Using statistics in clinical trials enables researchers to derive reasonable and accurate conclusions from the collected data, allowing them to make wise decisions in uncertain situations. In medical research, statistical methods are crucial for preventing errors and bias.
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Cognitive Practice Effects Delay Diagnosis; Implications for Clinical Trials.

Mark Sanderson-Cimino^1,2, Jeremy A Elman^2,3, Xin M Tu^3,4,5

¹San Diego State University/University of California San Diego Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA.

Medrxiv : the Preprint Server for Health Sciences

|November 11, 2020

Summary

This summary is machine-generated.

Adjusting cognitive test scores for practice effects enables earlier detection of mild cognitive impairment (MCI). This improves diagnostic accuracy and significantly reduces clinical trial costs and duration.

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Area of Science:

Neuroscience
Gerontology
Biomarkers

Background:

Practice effects on cognitive tests can mask cognitive decline, delaying the diagnosis of mild cognitive impairment (MCI).
Early detection of MCI is crucial for timely intervention and effective clinical trial design for Alzheimer's disease (AD).

Approach:

Developed a novel method to adjust cognitive test scores for practice effects and attrition.
Calculated practice effects by comparing follow-up scores of returning participants to demographically-matched individuals tested once.
Subtracted practice effects from follow-up scores to identify individuals who met MCI criteria after adjustment.

Key Points:

Practice-effect-adjusted diagnoses increased MCI incidence by 26%, improving the detection of amyloid-positive MCI cases.
Adjustment led to a 6% reduction in amyloid-positive cognitively normal individuals, enhancing diagnostic precision.
Adjusting for practice effects could reduce clinical trial sample sizes by 21%, leading to substantial cost savings.

Conclusions:

Adjusting cognitive test scores for practice effects facilitates earlier and more accurate MCI detection.
This adjustment improves diagnostic validity supported by biomarker evidence.
Earlier MCI detection through score adjustment reduces clinical trial burden, duration, and costs, enhancing research efficiency.