Evidence map›Paper›PMID 29854926›Full record

ArticleAlzheimer's & dementia (New York, N. Y.)2015

Effect of sample size re-estimation in adaptive clinical trials for Alzheimer's disease and mild cognitive impairment.

Guoqiao Wang, Richard E Kennedy, Gary R Cutter, Lon S Schneider

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Alzheimer's & dementia (New York, N. Y.), 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Article
  2. Observational
  3. Review
4 · The record

Corrections and comments

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5 · Who and what money

Authors and funding

4 authors.

Guoqiao WangDepartment of Biostatistics, University of Alabama-Birmingham, Birmingham, AL, USA.
Richard E KennedyDepartment of Medicine, University of Alabama-Birmingham, Birmingham, AL, USA.
Gary R CutterDepartment of Biostatistics, University of Alabama-Birmingham, Birmingham, AL, USA.
Lon S SchneiderDepartments of Psychiatry and Neurology, University of Southern California Keck School of Medicine, Los Angeles, CA, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionThe sample size re-estimation (SSR) adaptive design allows interim analyses and resultant modifications of the ongoing trial to preserve or increase power. We investigated the applicability of SSR in Alzheimer's disease (AD) trials using a meta-database of clinical studies.

methodsBased on six studies, we simulated clinical trials using Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-Cog) as primary outcome. A single SSR based on effect sizes or based on variances was conducted at 6 months and 12 months. Resultant power improvement and sample size adjustments were evaluated.

resultsSSR resulted in highly variable outcomes for both sample size increases and power improvement. The gain in power after SSR varies by initial sample sizes, trial durations, and effect sizes.

conclusionsSSR adaptive designs can be effective for trials in AD and mild cognitive impairment with small or medium initial sample sizes. However, SSR in larger trials (>200 subjects per arm) generates no major advantages over the typical randomized trials.

Indexed as

Adaptive designAlzheimer's diseaseAlzheimer's Disease Assessment ScaleMild cognitive impairmentSample size re-estimation

Identifiers

PMID29854926
PMCPMC5975045

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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.