Reassessing High-Performing LLMs on Polish Medical Exams: True Competence or Bias-Driven Performance?

Antoni Lasik, Jakub Pokrywka, Łukasz Grzybowski, Jeremi Ignacy Kaczmarek, Gabriela Korzańska, Janusz Świeczkowski-Feiz, Oskar Pastuszek, Paulina Hoffman, Jakub Tomasz Dabrowski, Wojciech Kusa


Abstract
Large language models (LLMs) in medicine are mainly evaluated using multiple-choice question answering (MCQA), which can overestimate real clinical ability due to guessing strategies and answer biases. To address these limitations, we introduce an expanded and more challenging benchmark based on Polish medical exams, adding over 15,000 questions, two new domains, and four structural modifications that reduce MCQA-specific artifacts and better test reasoning. We evaluate 21 LLMs and show that evaluation design strongly affects results. Under our harder setup, the best model (Qwen3.5-122B) drops by 28.4 and 31 pp on English and Polish exams, respectively. Despite low evidence of data contamination, standard MCQA scores do not reliably reflect true medical competence. To facilitate further research, we make our benchmark publicly available: https://github.com/NASK-NLP/Polish-Medical-Exams
Anthology ID:
2026.findings-emnlp.2394
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
51441–51467
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.2394/
DOI:
10.18653/2026.findings-emnlp.2394
Bibkey:
Cite (ACL):
Antoni Lasik, Jakub Pokrywka, Łukasz Grzybowski, Jeremi Ignacy Kaczmarek, Gabriela Korzańska, Janusz Świeczkowski-Feiz, Oskar Pastuszek, Paulina Hoffman, Jakub Tomasz Dabrowski, and Wojciech Kusa. 2026. Reassessing High-Performing LLMs on Polish Medical Exams: True Competence or Bias-Driven Performance?. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 51441–51467, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Reassessing High-Performing LLMs on Polish Medical Exams: True Competence or Bias-Driven Performance? (Lasik et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.2394.pdf