PreprintCited by 2Artificial Intelligence in Healthcare and EducationTopic ModelingMultimodal Machine Learning Applications

Can Large Language Models Self-Correct in Medical Question Answering? An Exploratory Study

Open access
Zhan, Zaifu, Cui, Mengyuan, Zhang, Rui·2026·2026 IEEE 14th International Conference on Healthcare Informatics (ICHI)

Abstract

Large language models (LLMs) have achieved strong performance on medical question answering (medical QA), and chain-of-thought (CoT) prompting has further improved results by eliciting explicit intermediate reasoning; meanwhile, self-reflective (self-corrective) prompting has been widely claimed to enhance model reliability by prompting LLMs to critique and revise their own reasoning, yet its effectiveness in safety-critical medical settings remains unclear. In this work, we conduct an exploratory analysis of self-reflective reasoning for medical multiple-choice question answering: using GPT-4o and GPT-4o-mini, we compare standard CoT prompting with an iterative self-reflection loop and track how predictions evolve across reflection steps on three widely used medical QA benchmarks (MedQA, HeadQA, and PubMedQA). We analyze whether self-reflection leads to error correction, error persistence, or the introduction of new errors. Our results show that self-reflective prompting does not consistently improve accuracy and its impact is highly dataset- and model-dependent: it yields modest gains on MedQA but provides limited or negative benefits on HeadQA and PubMedQA, and increasing the number of reflection steps does not guarantee better performance. These findings highlight a gap between reasoning transparency and reasoning correctness, suggesting that self-reflective reasoning is better viewed as an analytical tool for understanding model behavior rather than a standalone solution for improving medical QA reliability.

AI snapshot

Written from the paper’s full text.

TL;DR

This exploratory study compares chain-of-thought prompting with iterative self-reflection for medical multiple-choice QA using GPT-4o and GPT-4o-mini. Self-reflection does not consistently improve accuracy and is highly dataset- and model-dependent, suggesting it is better viewed as an analytical tool than a standalone reliability solution.

Key findings

  • Self-reflection produced modest gains on MedQA: GPT-4o improved from 87.80% to 88.80%, and GPT-4o-mini from 74.80% to 76.00%.
  • Effects were limited or negative on other benchmarks: HeadQA changed from 91.39% to 90.57% for GPT-4o and remained 79.10% for GPT-4o-mini; PubMedQA dropped from 70.80% to 69.00% for GPT-4o and from 71.60% to 69.60% for GPT-4o-mini.
  • Accuracy typically stabilized after a small number of reflection steps and did not improve monotonically up to 10 iterations; most instances terminated with 0–1 reflection steps, and over 85% of GPT-4o instances on each dataset required no additional reflection beyond the initial answer.
  • The paper concludes that self-reflection can correct some errors but can also preserve incorrect reasoning or introduce new errors, with larger models showing fewer reflection steps and more stable performance.

Methods

  • Exploratory design comparing a standard chain-of-thought baseline against an iterative self-reflection loop that prompts the model to review and revise its own reasoning, with up to K = 10 reflection attempts unless otherwise specified.
  • Evaluated GPT-4o and GPT-4o-mini via the OpenAI API in a zero-shot, black-box setting without parameter updates or fine-tuning, using official test splits of MedQA (1,273), HeadQA (244), and PubMedQA (500).
  • Tracked predictions at each reflection step and computed accuracy against ground-truth answers; if the model did not report satisfaction within the maximum attempts, a majority-vote answer over generated predictions was also computed for analysis.

Limitations

  • Stated: the study uses only prompt-based self-reflection without external supervision, retrieval, or verification signals, so reflection relies entirely on internal representations and may reinforce incorrect reasoning.
  • Stated: reflection is evaluated primarily at the answer level, which may limit intervention in earlier reasoning steps where errors originate, and experiments cover a limited set of multiple-choice medical QA benchmarks rather than open-ended clinical reasoning or real-world decision support.
  • Evident from the text: the analysis is exploratory and limited to two GPT-4o-family models accessed as black boxes, with no fine-tuning or training, so findings may not generalize to other model families or scales.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1109/ichi69079.2026.00215

Cites

27 of 27 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 6 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    ChatGPT-4o consistently requires fewer reflection steps than ChatGPT-4o-mini.

    “ChatGPT-4o consistently requires fewer reflection steps than ChatGPT-4o-mini”
    Quote in the paperSubstantial claim
  • Findingown data

    For ChatGPT-4o, over 85% of instances on each dataset require no additional reflection beyond the initial answer.

    “For ChatGPT-4o, over 85% of instances on each dataset require no additional reflection beyond the initial answer.”
    Quote in the paperSubstantial claim
  • Findingown data

    On HeadQA, ChatGPT-4o accuracy decreased slightly after self-reflection, from 91.39% to 90.57%.

    “on HeadQA, ChatGPT-4o slightly decreases after self-reflection (from 91.39% to 90.57%)”
    Quote in the paperSubstantial claim
  • Findingown data

    On PubMedQA, self-reflection decreased ChatGPT-4o accuracy from 70.80% to 69.00%.

    “on PubMedQA, self-reflection slightly degrades performance for both models (ChatGPT-4o: 70.80% → 69.00%”
    Quote in the paperSubstantial claim
  • Findingown data

    On MedQA, self-reflection increased ChatGPT-4o accuracy from 87.80% to 88.80%.

    “On MedQA, self-reflection yields modest gains for both models, increasing accuracy from 87.80% to 88.80% for ChatGPT-4o”
    Quote in the paperSubstantial claim
  • May combine two claims. 9
  • Classified as probably not a substantial claim. 9
  • May combine two claims.

    Findingown data

    ChatGPT-4o-mini engages in reflection more often than ChatGPT-4o, most notably on MedQA where a substantial portion of examples require multiple reflection steps.

    “ChatGPT-4o-mini engages in reflection more often, most notably on MedQA, where a substantial portion of examples require multiple reflection steps.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    Across datasets, accuracy typically stabilizes after a small number of reflection steps and does not improve monotonically as reflection continues.

    “Across datasets, accuracy typically stabilizes after a small number of steps and does not exhibit monotonic improvement as reflection continues.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data

    Reflection can occasionally correct initial errors, but it can also preserve incorrect reasoning or introduce new errors.

    “While reflection can occasionally correct initial errors, it can also preserve incorrect reasoning or introduce new errors.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data

    Larger models such as ChatGPT-4o tend to require fewer reflection steps and exhibit more stable performance, suggesting higher internal consistency in their initial chain-of-thought reasoning.

    “Larger models such as ChatGPT-4o tend to require fewer reflection steps and exhibit more stable performance, suggesting higher internal consistency in their initial chain-of-thought reasoning.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data

    Smaller models are more prone to engaging in reflection and show greater variability across reflection steps, indicating iterative self-evaluation may introduce instability rather than correction when underlying reasoning is weak.

    “Smaller models, while more prone to engaging in reflection, show greater variability across reflection steps, indicating that iterative selfevaluation may introduce instability rather than correction when underlying reasoning is weak.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Chain-of-thought prompting offers a practical benefit for interpretability and transparency by revealing an inspectable reasoning trace.

    “Beyond performance improvements, CoT prompting offers a practical benefit for interpretability and transparency [18]: it reveals a reasoning trace that can be inspected, compared, and analyzed”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [18]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The study evaluated self-reflection primarily at the answer level, which may limit its ability to intervene in earlier reasoning steps where errors originate.

    “we evaluate self-reflection primarily at the answer level, which may limit its ability to intervene in earlier reasoning steps where errors originate.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim.

    Study design and conductnone given

    All datasets were evaluated using their official test splits.

    “All datasets are evaluated using their official test splits”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data

    Self-reflection does not consistently improve performance; its effect depends on both the dataset and the model.

    “Overall, self-reflection does not consistently improve performance; instead, its effect depends on both the dataset and the model.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Chain-of-thought prompting has been shown to improve accuracy on tasks that require step-by-step reasoning.

    “By explicitly instructing LLMs to produce intermediate reasoning steps before committing to a final answer, CoT prompting has been shown to improve accuracy on tasks that require step-by-step reasoning.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [14]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Premisecitation

    MedQA-USMLE is designed to assess multi-step clinical reasoning, differential diagnosis, and hypothesis evaluation rather than merely retrieving isolated facts.

    “MedQA-USMLE is designed to assess whether models can perform multi-step clinical reasoning, differential diagnosis, and hypothesis evaluation, rather than merely retrieving isolated facts.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [13]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    Self-reflection encourages explicit reasoning and self-evaluation but does not ensure error correction.

    “although self-reflection encourages explicit reasoning and self-evaluation, it does not ensure error correction.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning

    MedQA questions often involve multi-step clinical reasoning and differential diagnosis, where revisiting intermediate assumptions may occasionally help identify overlooked inconsistencies.

    “MedQA questions often involve multi-step clinical reasoning and differential diagnosis, where revisiting intermediate assumptions may occasionally help identify overlooked inconsistencies.”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    PubMedQA is a biomedical QA dataset constructed from PubMed abstracts, requiring reasoning grounded in scientific evidence rather than exam-style clinical heuristics.

    “PubMedQA [26] is a biomedical question answering dataset constructed from PubMed abstracts, requiring reasoning grounded in scientific evidence rather than exam-style clinical heuristics.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [26]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Premisecitation

    Medical QA is inherently challenging because it requires broad biomedical knowledge, domain-specific terminology understanding, multi-step reasoning, and integrating evidence under uncertainty.

    “medical QA is inherently challenging because it requires a combination of broad biomedical knowledge, domain-specific terminology understanding, multi-step reasoning, and the ability to integrate evidence under uncertainty [12].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [12]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    The dataset-dependent behavior may be explained by the nature of the reasoning required by different medical QA benchmarks.

    “One possible explanation for the dataset-dependent behavior observed in our results lies in the nature of the reasoning required by different medical QA benchmarks.”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim.

    Interpretationreasoning

    HeadQA, while exam-based, tends to be more structured, leaving fewer opportunities for reflection-driven revision once an initial reasoning path has been formed.

    “HeadQA, while also exam-based, tends to be more structured, leaving fewer opportunities for reflection-driven revision once an initial reasoning path has been formed.”
    Quote in the paperSubstantial claim
17 of 17
  • The paper relies on this without support.

    Incorrect conclusions accompanied by coherent and confident explanations may increase user trust despite being wrong.

    “incorrect conclusions accompanied by coherent and confident explanations may increase user trust despite being wrong.”
  • The paper relies on this without support.

    Self-reflection operates purely at inference time without additional training data, fine-tuning, or parameter updates, making it broadly applicable to black-box models accessed via APIs.

    “it operates purely at inference time, without requiring additional training data, fine-tuning, or parameter updates, making it broadly applicable to black-box models accessed via APIs.”
  • The paper relies on this without support.

    The three medical QA benchmarks cover complementary sources of medical knowledge and reasoning demands.

    “three widely used medical QA benchmarks that cover complementary sources of medical knowledge and reasoning demands.”
  • The paper relies on this without support.

    The effectiveness and reliability of self-reflection in medical question answering remain insufficiently characterized.

    “its effectiveness and reliability in medical question answering remain insufficiently characterized.”
  • The paper relies on this without support.

    Medicine is a safety-critical domain, so evaluation of LLMs must consider reliability, robustness, and trustworthiness in addition to accuracy.

    “because medicine is a safety-critical domain, the evaluation of LLMs must consider not only accuracy but also reliability, robustness, and trustworthiness”
5 of 5

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Vilares, HEAD-QA: A healthcare dataset for complex reasoning, 960

Cited by

Sorted by citations

Authors
Zhan, Z., Cui, M., & Zhang, R.
Affiliations
  • University of Minnesota (US)
  • University of St. Thomas
Venue
2026 IEEE 14th International Conference on Healthcare Informatics (ICHI)
Publisher
IEEE
Published
2026-06
Pages
1388-1390
OpenAlex
W7148483564
Cited by
0
References
3
FWCI
0.00
Type
conference paper
Open access
Locations
  • IEEE International Conference on Healthcare Informatics (ICHI) (publishedVersion)
  • arXiv (Cornell University) (submittedVersion)
  • arXiv (Cornell University)
Funders
  • National Center for Complementary and Integrative Health
  • National Institute on Aging
  • National Cancer Institute
  • National Institute of Diabetes and Digestive and Kidney Diseases
  • National Institute on Minority Health and Health Disparities
Topics
  • Health Sciences › Medicine › Health Informatics › Artificial Intelligence in Healthcare and Education
  • Physical Sciences › Computer Science › Artificial Intelligence › Topic Modeling
  • Physical Sciences › Computer Science › Computer Vision and Pattern Recognition › Multimodal Machine Learning Applications
Keywords
large language models, medical question answering, chain-of-thought prompting, multiple-choice question answering, error correction, GPT-4o, MedQA, PubMedQA

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