PreprintCited by 11Artificial Intelligence in Healthcare and EducationMachine Learning in HealthcareArtificial Intelligence in Healthcare

Benchmarking the Confidence of Large Language Models in Clinical Questions

Open access
Omar, Mahmud, Agbareia, Reem, Glicksberg, Benjamin S, Nadkarni, Girish N, Klang, Eyal·2024·medRxiv

Abstract

Background and Aim: The capabilities of large language models (LLMs) to self-assess their own confidence in answering questions in the biomedical realm remain underexplored. This study evaluates the confidence levels of 12 LLMs across five medical specialties to assess their ability to accurately judge their responses. Methods: We used 1,965 multiple-choice questions assessing clinical knowledge from internal medicine, obstetrics and gynecology, psychiatry, pediatrics, and general surgery areas. Models were prompted to provide answers and to also provide their confidence for the correct answer (0–100). The confidence rates and the correlation between accuracy and confidence were analyzed. Results: There was an inverse correlation (r=-0.40, p=0.001) between confidence and accuracy, where worse performing models showed paradoxically higher confidence. For instance, a top performing model, GPT4o had a mean accuracy of 74% with a mean confidence of 63%, compared to a least performant model, Qwen-2-7B, which showed mean accuracy 46% but mean confidence 76%. The mean difference in confidence between correct and incorrect responses was low for all models, ranging from 0.6% to 5.4%, with GPT4o having the highest differentiation of 5.4%. Conclusion: Better performing LLMs show more aligned overall confidence levels. However, even the most accurate models still show minimal variation in confidence between right and wrong answers. This underscores an important limitation in current LLMs’ self-assessment mechanisms, highlighting the need for further research before integration into clinical settings.

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Registry

Crossref · 10.1101/2024.08.11.24311810

Cites

26 of 26 references verified0 citation errors · 0 not checkable

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  • Omar et al. (2024) have shown that across multiple specialties, current LLMs frequently assign high confidence to incorrect answers, revealing poor calibration in clinical settings.

    “Studies such as Omar et al. (2024) have shown that across multiple specialties, current LLMs frequently assign high confidence to incorrect answers, revealing poor calibration in clinical settings.”

    From Trustworthy Medical Question Answering: An Evaluation-Centric Survey (2025) · cites this paper as Omar et al., 2024

  • Verbalized confidence is known to be overconfident in clinical question answering.

    “While verbalized confidence is known to be overconfident in clinical question answering [38], our results contradict recent work that suggests that consistency-based methods alleviate some of these concerns [39].”

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Authors
Omar, M., Agbareia, R., Glicksberg, B. S., Nadkarni, G. N., & Klang, E.
Affiliations
Icahn School of Medicine at Mount Sinai (US)
Corresponding author
Omar, Mahmud
Venue
medRxiv
Publisher
openRxiv
Published
2024-08-11
OpenAlex
W4401498253
Cited by
10
References
24
Citations by year
2026: 4 · 2025: 5 · 2024: 1
Type
posted content
Language
en
Open access
Locations
medRxiv (acceptedVersion, cc-by-nc-nd)
Topics
  • Health Sciences › Medicine › Health Informatics › Artificial Intelligence in Healthcare and Education
  • Physical Sciences › Computer Science › Artificial Intelligence › Machine Learning in Healthcare
  • Health Sciences › Health Professions › Health Information Management › Artificial Intelligence in Healthcare
Keywords
large language models, confidence calibration, self-assessment, clinical knowledge, multiple-choice questions, medical specialties, GPT-4o, benchmarking, clinical decision support

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