Limics at #SMM4H-HeaRD 2026: Uncertainty-Driven Prediction for ADE Detection in Social Media

Nour Allam


Abstract
This paper describes our system for the SMM4H-HeaRD 2026 Task 1: Detection of Adverse Drug Events in Multilingual and Multi-platform Social Media Posts. We developed a two-stage pipeline combining a fine-tuned XLM-RoBERTa-large encoder-only model with a large language model for final decision on ambiguous cases. To handle complex linguistic boundaries, we explore explicitly training the encoder to treat ambiguity as a discrete third label to delegate those cases to the generative model. Although introducing the third label was associated with lower performance than relying on a binary model, when using the encoder as a preliminary filter for classifying 78.62% of posts as negatives, we achieved a global F1 score of 0.614 (+0.034 over task median).
Anthology ID:
2026.smm4h-1.37
Volume:
Proceedings of the 11th Social Media Mining for Health Research and Applications (SMM4H-HeaRD 2026) Workshop and Shared Tasks
Month:
July
Year:
2026
Address:
San Diego, United States
Editors:
Guillermo Lopez-Garcia, Graciela Gonzalez-Hernandez
Venues:
SMM4H | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
230–236
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.smm4h-1.37/
DOI:
Bibkey:
Cite (ACL):
Nour Allam. 2026. Limics at #SMM4H-HeaRD 2026: Uncertainty-Driven Prediction for ADE Detection in Social Media. In Proceedings of the 11th Social Media Mining for Health Research and Applications (SMM4H-HeaRD 2026) Workshop and Shared Tasks, pages 230–236, San Diego, United States. Association for Computational Linguistics.
Cite (Informal):
Limics at #SMM4H-HeaRD 2026: Uncertainty-Driven Prediction for ADE Detection in Social Media (Allam, SMM4H 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.smm4h-1.37.pdf