The Editorial Expression of Concern: Science's Early Warning System

How journals alert readers to potential problems in research without waiting for a final verdict

Introduction

In the vast and ever-expanding library of scientific knowledge, how can readers be alerted to potential problems in a research paper without waiting for a final verdict? Imagine a "caution" sign placed on a published study, signaling to the scientific community that questions have emerged that require further investigation. This is precisely the role of an Editorial Expression of Concern—a crucial but often misunderstood mechanism in the self-correcting machinery of science.

Issued by journal editors or publishers, an Editorial Expression of Concern serves as a formal notice that a publication may contain errors or be otherwise untrustworthy, while falling short of a full retraction. These expressions are increasingly common in today's scientific landscape, with data showing that over half of all such notices in PubMed were issued between 2014 and 2016 alone 2 . Understanding this process provides a fascinating window into how science polices itself, balancing the need for prompt warning with the requirement for due process.

What Exactly is an Editorial Expression of Concern?

An Editorial Expression of Concern is a publisher's note regarding concerns raised about a publication. It represents a middle ground in scientific publishing—not as definitive as a retraction, but more serious than a simple correction. According to the Committee on Publication Ethics, these notices aim to draw attention to potential problems in a publication without itself constituting a retraction or correction 2 .

When is an Expression of Concern Used?

Journals typically issue these expressions under specific circumstances recommended by organizations like COPE and the International Committee of Medical Journal Editors 4 :

  • When there's inconclusive evidence of research or publication misconduct
  • When findings appear unreliable but the authors' institution won't investigate
  • When an investigation is underway but a judgment won't be available for some time
  • When there are concerns about the fairness or conclusiveness of an investigation

Unlike retractions, which require more definitive evidence of problems, Expressions of Concern allow editors to alert readers promptly while investigations are ongoing, serving as a temporary safeguard for the scientific record.

Key Characteristics
Warning Signal

Alerts readers to potential issues without definitive conclusion

Temporary Measure

Often issued while investigations are ongoing

Due Process

Balances transparency with fairness to authors

A Closer Look: The Rising Tide of Concerns

The use of Editorial Expressions of Concern, while still relatively rare, has been steadily increasing. A comprehensive descriptive study published in Research Integrity and Peer Review identified 230 EEoCs affecting 300 publications in PubMed up to August 2016, with the earliest issued in 1985 2 . Strikingly, 52% of these were issued between 2014 and 2016, indicating a growing recognition of their importance in maintaining scientific integrity.

EEoC Publication Trends Over Time
Key Statistics

52%

of all EEoCs in PubMed were issued between 2014 and 2016 2

29%

of publications with EEoCs were eventually retracted 2

31%

of EEoC cases remained open with no final resolution 2

What Happens After an Expression of Concern?

The same study revealed that only about 29% of publications with Expressions of Concern were eventually retracted by late 2016 2 . This suggests that most concerns either remain unresolved or are eventually resolved without needing retraction. The data shows that:

68%

of EEoCs were issued due to concerns with the validity of data, methods, or interpretation 2

40%

of affected publications had issues with images 2

31%

of cases remained open with no final resolution 2

Outcomes of Editorial Expressions of Concern (Based on 2017 Study) 2
Outcome Percentage Description
Retracted 29% Articles eventually fully retracted
Resolved Otherwise 40% Concerns addressed without retraction
Remain Open 31% No final resolution as of study completion

Case Study: A Real-World Expression of Concern

The Nanoscale Metal-Organic Frameworks Study

In March 2024, Science Advances published an Editorial Expression of Concern regarding a 2020 research article titled "Nanoscale metal-organic frameworks for x-ray activated in situ cancer vaccination" by Ni et al. 1

The notice stated that the University of Chicago had informed the journal about "apparent partial overlap between the confocal images of two control groups in the Supplementary Materials." Essentially, there were concerns that images meant to represent different experimental conditions might have been inappropriately duplicated or overlapped.

Rather than immediately retracting the paper, the journal chose the Expression of Concern pathway, noting that "the authors repeat the experiments for the supplementary figures in question." This approach balanced the need to alert the scientific community with allowing the authors to demonstrate the robustness of their findings through replication.

How Such Cases Typically Unfold

Identification of Potential Issues

Problems may be spotted by readers, reviewers, or occasionally by the authors themselves 3

Journal Investigation

Editors assess the credibility of the concerns

Institutional Involvement

The authors' institution may be contacted to investigate

Decision Point

Editors determine whether an Expression of Concern is warranted

Resolution

The process may eventually lead to correction, retraction, or clearance of concerns

Common Triggers for Editorial Expressions of Concern 2
Trigger Category Specific Issues Frequency in EEoCs
Data Integrity Image manipulation, data fabrication, methodological errors 68% (validity concerns)
Ethical Concerns Plagiarism, authorship disputes, ethical violations Not specified in results
External Factors Institutional investigations, legal proceedings 31% (ongoing investigations)

The Scientist's Toolkit: Understanding Research Integrity Mechanisms

Scientific publishing employs several mechanisms to maintain research integrity, with Editorial Expressions of Concern being just one tool in the toolbox.

Key Mechanisms in Research Integrity 3 4
Mechanism Purpose When Used
Erratum/Corrigendum Correct minor errors that don't affect conclusions Author or publisher mistakes in published work
Editorial Expression of Concern Alert readers to potentially serious issues Concerns about integrity while investigation is ongoing
Retraction Remove seriously flawed or unethical work Confirmed scientific misconduct or irreproducible findings
Addendum Add significant information New findings crucial to understanding the work

These mechanisms operate under guidelines from organizations like the Committee on Publication Ethics and the International Committee of Medical Journal Editors, which help standardize practices across journals 3 4 .

Correction

For minor errors that don't affect the main conclusions

Expression of Concern

For potential serious issues requiring investigation

Retraction

For confirmed serious flaws or misconduct

Addendum

For adding important information to existing work

Why Expressions of Concern Matter

Editorial Expressions of Concern serve several critical functions in the scientific ecosystem:

Timely Warning

They provide prompt notification of potential problems without waiting for lengthy investigations to conclude

Transparency

They make the scientific process more open by acknowledging that even published work may have issues

Due Process

They allow for proper investigation while minimizing premature judgments

Record Preservation

Unlike removal of articles, they maintain the scientific record while flagging concerns

As noted by Wolters Kluwer publishers, "An expression of concern is used to raise awareness to readers that an article may be unreliable. It may be a precursor to a full retraction, but not always" 3 .

Conclusion: Vigilance in Scientific Progress

Editorial Expressions of Concern represent an important development in science's ongoing effort to self-correct. They acknowledge that scientific publishing is a human endeavor—subject to error, misunderstanding, and occasionally misconduct—while providing a measured response that protects both the scientific record and the rights of those involved.

As the 2017 study concluded, while EEoCs have been "rare publishing events in the biomedical literature, their use has been increasing" 2 . This trend likely reflects growing vigilance rather than increasing problems—a positive sign for scientific integrity.

The next time you encounter an Editorial Expression of Concern while reading scientific literature, recognize it not as a sign of system failure, but as evidence of science's robust mechanisms for course correction. It represents the scientific community's commitment to truth-seeking, demonstrating that vigilance continues long after publication day.

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