IITPatna_ADE at #SMM4H-HeaRD 2026: Multilingual Adverse Drug Event Detection with LoRA-XLM-RoBERTa, Cross-Fold Ensembles, and Post-hoc Calibration
Summary
The IITPatna_ADE system, submitted to Task 1 of #SMM4H-HeaRD 2026, addresses multilingual binary classification of adverse drug event (ADE) mentions in social media. This system fine-tunes "xlm-roberta-large" using LoRA adapters and learned language embeddings. Its training involves a two-stage process: initial domain adaptation with translated CADEC data, followed by five-fold cross-validation on the official training set. The approach further incorporates an ensemble of the five fold checkpoints via mean logits, applies temperature scaling on the development set, and tunes decision thresholds to optimize the official metric. On the development set, the ensemble achieved a macro-F1 of 0.788 with a global threshold and 0.796 with per-language thresholds. The best official test submission recorded a macro-F1 of 0.616 (ID 678990).
Key takeaway
For NLP Engineers developing multilingual health information extraction systems, this work demonstrates a robust methodology for adverse drug event detection. You should consider integrating LoRA-based fine-tuning with "xlm-roberta-large" for efficiency and performance. Implementing a two-stage training approach, combining domain adaptation with cross-validation, alongside ensemble methods and post-hoc calibration, can significantly improve macro-F1 scores in similar social media text classification tasks.
Key insights
Multilingual ADE detection benefits from LoRA-XLM-RoBERTa, two-stage training, cross-fold ensembles, and post-hoc calibration.
Principles
- Two-stage training improves domain adaptation.
- Ensembling cross-validation checkpoints enhances robustness.
- Post-hoc calibration refines model output for specific metrics.
Method
Fine-tune "xlm-roberta-large" with LoRA and language embeddings. Use two-stage training (CADEC domain adaptation, then 5-fold CV). Ensemble checkpoints by mean logits, apply temperature scaling, and tune decision thresholds.
In practice
- Implement LoRA for efficient fine-tuning of large models.
- Utilize cross-validation ensembles for robust predictions.
- Apply temperature scaling and threshold tuning for metric optimization.
Topics
- Multilingual NLP
- Adverse Drug Event Detection
- LoRA
- XLM-RoBERTa
- Ensemble Learning
- Social Media Mining
- Post-hoc Calibration
Best for: Research Scientist, AI Scientist, Machine Learning Engineer, NLP Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by Paper Index on ACL Anthology.