Evidence map›Paper›PMID 34010281›Full record

ArticlePLoS biology2021

Meta-analysis of variation suggests that embracing variability improves both replicability and generalizability in preclinical research.

Takuji Usui, Malcolm R Macleod, Sarah K McCann, Alistair M Senior, Shinichi Nakagawa

Open access · goldAbstract read
In one paragraph

Article in PLoS biology, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 34 papers, 6 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
34citing papers in PubMed, 6 pooled it
5.0field-weighted citation impact, top 1% of its field
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

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.

3 · Its place in the literature

Who cites it

34 citing papers in PubMed, 6 syntheses or guidelines pooled it, 70 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. ClinicalFrontiers in microbiology · 2025
    Pooled it
  5. Guideline
  6. Pooled it
  7. Article
  8. Article
  9. Review
  10. Reconfiguration of brain-wide neural activity after early life adversity.Proceedings of the National Academy of Sciences of the United States of America · 2025
    Article
  11. Reconfiguration of brain-wide neural activity after early life adversity.bioRxiv : the preprint server for biology · 2025
    Article
  12. Article
  13. Article
  14. Article
  15. Article
  16. Article
  17. Article
  18. Article
  19. Article
  20. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 3 institutions in 3 countries.

Takuji UsuiEvolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia.
Malcolm R MacleodCentre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom.ORCID 0000-0001-9187-9839
Sarah K McCannQUEST Center for Transforming Biomedical Research, Berlin Institute of Health (BIH), Berlin, Germany.ORCID 0000-0003-4737-2349
Alistair M SeniorThe Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia.ORCID 0000-0001-9805-7280
Shinichi NakagawaEvolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia.ORCID 0000-0002-7765-5182
The University of Sydney · AUHumboldt-Universität zu Berlin · DEUniversity of Edinburgh · GB

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The replicability of research results has been a cause of increasing concern to the scientific community. The long-held belief that experimental standardization begets replicability has also been recently challenged, with the observation that the reduction of variability within studies can lead to idiosyncratic, lab-specific results that cannot be replicated. An alternative approach is to, instead, deliberately introduce heterogeneity, known as "heterogenization" of experimental design. Here, we explore a novel perspective in the heterogenization program in a meta-analysis of variability in observed phenotypic outcomes in both control and experimental animal models of ischemic stroke. First, by quantifying interindividual variability across control groups, we illustrate that the amount of heterogeneity in disease state (infarct volume) differs according to methodological approach, for example, in disease induction methods and disease models. We argue that such methods may improve replicability by creating diverse and representative distribution of baseline disease state in the reference group, against which treatment efficacy is assessed. Second, we illustrate how meta-analysis can be used to simultaneously assess efficacy and stability (i.e., mean effect and among-individual variability). We identify treatments that have efficacy and are generalizable to the population level (i.e., low interindividual variability), as well as those where there is high interindividual variability in response; for these, latter treatments translation to a clinical setting may require nuance. We argue that by embracing rather than seeking to minimize variability in phenotypic outcomes, we can motivate the shift toward heterogenization and improve both the replicability and generalizability of preclinical research.

Indexed as

Animal ExperimentationAnimalsBehavior, AnimalBrain IschemiaHumansMeta-Analysis as TopicModels, AnimalPhenotypeReference StandardsReproducibility of ResultsResearch DesignStroke

Identifiers

PMID34010281
PMCPMC8168858
OpenAlexW3162160784

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.