Evidence map›Paper›PMID 16060722›Full record

ArticlePLoS medicine2005

Why most published research findings are false.

John P A Ioannidis

Erratum issuedAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in PLoS medicine, 2005. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 2,910 papers, 18 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
2,910citing papers in PubMed, 18 pooled it
–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

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

2,910 citing papers in PubMed, 18 syntheses or guidelines pooled it.

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  7. Auditory Sensitivity in Autism: A Systematic Review of Mismatch Negativity and Mismatch Field Responses.Autism research : official journal of the International Society for Autism Research · 2026
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  13. Bayesian Estimation Improves Prediction of Outcomes After Epilepsy Surgery.Annals of clinical and translational neurology · 2026
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2,850 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

1 author.

John P A IoannidisDepartment of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece. jioannid@cc.uoi.gr

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

There is increasing concern that most current published research findings are false. The probability that a research claim is true may depend on study power and bias, the number of other studies on the same question, and, importantly, the ratio of true to no relationships among the relationships probed in each scientific field. In this framework, a research finding is less likely to be true when the studies conducted in a field are smaller; when effect sizes are smaller; when there is a greater number and lesser preselection of tested relationships; where there is greater flexibility in designs, definitions, outcomes, and analytical modes; when there is greater financial and other interest and prejudice; and when more teams are involved in a scientific field in chase of statistical significance. Simulations show that for most study designs and settings, it is more likely for a research claim to be false than true. Moreover, for many current scientific fields, claimed research findings may often be simply accurate measures of the prevailing bias. In this essay, I discuss the implications of these problems for the conduct and interpretation of research.

Indexed as

BiasData Interpretation, StatisticalPublishingResearch DesignLikelihood FunctionsMeta-Analysis as TopicOdds RatioReproducibility of ResultsSample Size

Identifiers

PMID16060722
PMCPMC1182327

What OpenQuestion holds

Textmetadata
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.