Towards Fair and Efficient De-identification: Quantifying the Efficiency and Generalizability of De-identification Approaches
Paper · 2026 · Noopur Zambare, Kiana Aghakasiri, Carissa Lin et al.
Summary
Clinical notes must have personal identifiers removed before they can be shared, and recent studies increasingly use very large LLMs for this. The authors ask two questions. How much do such models cost at inference time compared with lighter alternatives? And do de-identifiers stay reliable across note formats, genders, and identifiers following non-Anglophone naming conventions? They benchmark fine-tuned BERT, ClinicalBERT and ModernBERT, small Llama and Qwen models (about 1–8B parameters), Llama 3.3-70B, Qwen2.5-72B and rule-based tools. The test data are MIMIC-III discharge summaries and a private set of rheumatology referral letters, with synthetic identifiers from several locales inserted via the Faker library. The large LLMs process text roughly an order of magnitude more slowly, while compact models perform comparably. Encoders fine-tuned on a few hundred notes can even beat the large models on culturally diverse identifiers. No gender-related gap appeared. The released BERT-MultiCulture-DEID models were trained on multi-locale identifiers and generalize better across cultures. They give hospitals a cheaper and fairer de-identification option.
Key points
- Models compared: BERT, ClinicalBERT and ModernBERT were tested alongside Llama (1B/3B/8B) and Qwen (1.5B/3B/7B) and the large Llama 3.3-70B and Qwen2.5-72B. Efficiency was measured as words processed per second against recall.
- Data:
- 4,000 MIMIC-III discharge summaries: 2,000 for training (subsets of 250/500/1,000/2,000), 1,000 for validation and 1,000 held out for testing.
- A proprietary rheumatology referral-letter corpus, used to test transfer across formats.
- Cultural test sets: Identifiers were drawn from Mandarin, Hindi, Spanish, French and Bengali, plus regional English variants. Gendered names were also checked, and no performance disparity by gender was found.
- Fine-tuning results: Going from 250 to 1,000 training notes improved performance only slightly. After training on all language variants, most models showed a generalization gap under 1%.
- Released resource: BERT-MultiCulture-DEID is a set of BERT, ClinicalBERT and ModernBERT models fine-tuned on MIMIC with multi-variant identifiers. It is intended as a more robust alternative to the widely used OBI de-identification model and is available via Zenodo (doi 10.5281/zenodo.18342291).
Institutions
Fields, topics and concepts
📚 Shelves 4The field of science this work belongs to (OpenAlex fields).Computer Science · 18,614 worksArtificial Intelligence · 17,965 worksArts and Humanities · 17,450 worksLanguage and Linguistics · 17,296 works
Cite
Cite as Noopur Zambare, Kiana Aghakasiri, Carissa Lin, Carrie Ye, J Ross Mitchell and Mohamed Abdalla. 2026. Towards Fair and Efficient De-identification: Quantifying the Efficiency and Generalizability of De-identification Approaches. Findings of the Association for Computational Linguistics: EACL 2026.
@inproceedings{zambare2026fair,
title = {{Towards Fair and Efficient De-identification: Quantifying the Efficiency and Generalizability of De-identification Approaches}},
author = {Noopur Zambare, Kiana Aghakasiri, Carissa Lin, Carrie Ye, J Ross Mitchell and Mohamed Abdalla},
booktitle = {Findings of the Association for Computational Linguistics: EACL 2026},
year = {2026},
doi = {10.18653/v1/2026.findings-eacl.222},
url = {https://doi.org/10.18653/v1/2026.findings-eacl.222}
}References
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