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A kNN based machine learning approach to automating causality assessment of adverse events
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  • Open access
  • Published: 15 February 2026

A kNN based machine learning approach to automating causality assessment of adverse events

  • Jun Ren1,
  • Hua Carroll2,
  • Kerry McCarthy2,
  • Jeff Allen1,
  • Jeff Tam1,
  • Jeffrey Philip1,
  • Monica Mehta2 &
  • …
  • Douglas Clark1 

Scientific Reports , Article number:  (2026) Cite this article

We are providing an unedited version of this manuscript to give early access to its findings. Before final publication, the manuscript will undergo further editing. Please note there may be errors present which affect the content, and all legal disclaimers apply.

Subjects

  • Drug development
  • Medical research

Abstract

This paper introduces a machine learning classifier designed to automate causality assessment in Individual Case Safety Reports (ICSRs), utilizing the principle of event similarity. The classifier’s effectiveness was evaluated using adverse events from six marketed products. Furthermore, we incorporated an augmentation tool to efficiently manage the classification of ‘unassessable’ adverse events. To enhance medical review oversight, we developed a web-based application serving as a reliable decision-support tool for medical reviewers. The outcomes obtained from our model were highly encouraging, emphasizing the potential advantages of utilizing such a model in ICSR causality assessment.

Data availability

The data is sensitive, proprietary, post-marketing adverse event data and is not available for sharing. However, inquiries regarding the data or the study can be directed to the corresponding author Jun Ren at jun.ren@biogen.com

References

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Funding

This research was funded by Biogen.

Author information

Authors and Affiliations

  1. Technology, Analytics & Data Insights (TADI), Biogen, Cambridge, MA, 02142, USA

    Jun Ren, Jeff Allen, Jeff Tam, Jeffrey Philip & Douglas Clark

  2. Global PV, Reg Submissions Mgt, PV/Reg Quality, Biogen, Cambridge, MA, 02142, USA

    Hua Carroll, Kerry McCarthy & Monica Mehta

Authors
  1. Jun Ren
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  2. Hua Carroll
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  3. Kerry McCarthy
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  4. Jeff Allen
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  5. Jeff Tam
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  6. Jeffrey Philip
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  7. Monica Mehta
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  8. Douglas Clark
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Contributions

Jun Ren and Hua Carroll led the model development effort and model augmentation activities. All authors contributed to the manuscript in accordance with the guidance. All authors read and approved the final version.

Corresponding author

Correspondence to Jun Ren.

Ethics declarations

Competing interests

All authors are employees of Biogen. The authors declare no competing interests.

Ethics aproval

The research only utilized post-marketing AE data.

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Supplementary Information

Supplementary Information 1.

Supplementary Information 2.

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Cite this article

Ren, J., Carroll, H., McCarthy, K. et al. A kNN based machine learning approach to automating causality assessment of adverse events. Sci Rep (2026). https://doi.org/10.1038/s41598-026-40267-2

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  • Received: 13 May 2025

  • Accepted: 11 February 2026

  • Published: 15 February 2026

  • DOI: https://doi.org/10.1038/s41598-026-40267-2

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Keywords

  • Pharmacovigilance
  • ICSR
  • Causality Assessment
  • Machine Learning
  • Similarity
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