MIRA: A Bilingual Benchmark for Medical Information Response Audit

Mengyu Xu, Qiaoxin Yang, Qianqian Wang, Xiwei Dai, Weiyi Wu, Chongyang Gao


Abstract
Existing safety evaluations for large language models overlook whether responses preserve comparable medical information across different user phrasings of the same question. To address this, we introduce the Medical Information Response Audit (MIRA), a bilingual, controlled benchmark that assesses whether LLMs provide comparable medical information across user-side language, register, and health literacy signals. MIRA contains 4,320 prompts built from 60 medically reviewed, low-risk health questions. Across five mainstream LLMs, models answered all medical questions, but responses to low health-literacy signals consistently omitted more key information, provided fewer concrete next steps, and offered less support for independent judgment. We term this pattern Differential Information Dilution (DID). A comparison with 300 real-world health queries provides preliminary evidence of rank-order validity. A knowledge-guided mitigation prompt reduces information dilution for most models, with the largest reductions in underinformative simplification observed for Claude (∼8%) and Qwen (∼6%).
Anthology ID:
2026.emnlp-main.719
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
16683–16705
Language:
URL:
https://aclanthology.org/2026.emnlp-main.719/
DOI:
Bibkey:
Cite (ACL):
Mengyu Xu, Qiaoxin Yang, Qianqian Wang, Xiwei Dai, Weiyi Wu, and Chongyang Gao. 2026. MIRA: A Bilingual Benchmark for Medical Information Response Audit. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 16683–16705, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
MIRA: A Bilingual Benchmark for Medical Information Response Audit (Xu et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.719.pdf