Retrieve-Then-Verify for Evaluating Evidence Support and Hallucination in Large Language Model–Generated Medical Information: Empirical Study
Open accessPublished version of a preprint
Abstract
Background: Despite high reported accuracy on clinical and evidence appraisal tasks, AI-generated medical information may lack explicit support from source documents. This creates challenges for digital health practitioners regarding transparency, auditability, and trust when AI systems are used for evidence synthesis, guideline development, and clinical knowledge management. Large language models (LLMs) can generate fluent and seemingly correct outputs, but existing evaluations often rely on agreement with human judgments and do not directly assess whether AI-generated content is grounded in underlying evidence. Objective: This study measures evidence support and hallucination in AI-generated medical information by assessing the extent to which LLM-generated risk-of-bias assessments are supported by source clinical trial reports. Methods: We evaluated 3 LLMs (GPT-5, OpenAI o3-mini, and GPT-3.5) on risk-of-bias (RoB 2) assessment using all 97 randomized controlled trials for which the source Cochrane systematic review provided complete human RoB 2 annotations and full-text reports were accessible, constituting the complete reference set. No train-validation split was applied; all 97 studies were used for evaluation. Model outputs were constrained to structured RoB 2 signaling questions and domain-level judgments. For each generated claim, relevant text passages were retrieved from trial reports using the Okapi BM25 (Best Matching 25) algorithm. A verification step assigned evidence verdicts (supported, contradicted, not found, or out of scope) with verbatim quotations. We quantified evidence support rates and conservative and strict hallucination rates. Task performance was evaluated using exact and binary accuracy, sensitivity, specificity, F1-score, Youden J, and agreement with human reviewers using Cohen κ and Fleiss κ. Results: Binary accuracy of AI-generated risk-of-bias judgments was high across domains (90%-98%), whereas exact accuracy was substantially lower (42%-71%), reflecting frequent disagreements in severity classification despite correct directional classification. GPT-5 achieved the strongest overall performance, including perfect binary accuracy for overall risk-of-bias conclusions and the highest agreement with human reviewers (quadratic κ up to 0.81). However, evidence support rates across models ranged from only 60% to 65%, with conservative hallucination rates of 34%-37%. GPT-5 showed the highest mean evidence support (64.3%) and the lowest strict hallucination rate (35.7%). Mean top-1 BM25 retrieval scores were similar across models (approximately 30-31), suggesting that differences in hallucination were not primarily attributable to differences in retrieval strength. Conclusions: AI-generated medical information can achieve high decision-level accuracy while still lacking documentary support in a substantial proportion of outputs. Measuring evidence support and hallucination reveals important limitations that are not captured by agreement metrics alone. Retrieval-based evidence verification provides a reproducible and transparent approach for evaluating the reliability of AI-generated medical information, with direct relevance to digital health practice, evidence-based medicine, and medical informatics.
AI snapshot
Written from the paper’s full text.
TL;DR
This empirical study introduces a retrieve-then-verify (RtV) framework to measure whether LLM-generated medical claims are supported by source documents, using Cochrane RoB 2 assessment across 97 randomized controlled trials. It finds that high decision-level accuracy and human agreement can coexist with substantial lack of documentary support, with evidence support only 60%-65% and conservative hallucination rates of 34%-37%.
Key findings
- Binary accuracy of AI-generated RoB judgments was high across domains (90%-98%), but exact accuracy was much lower (42%-71%), showing frequent severity-classification disagreements despite correct directional judgments.
- Evidence support rates ranged from only 60% to 65% across models; conservative hallucination rates were 34%-37%, and GPT-5 had the highest mean evidence support (64.3%) and lowest strict hallucination rate (35.7%).
- The accuracy-support gap ranged from 11% to 37% across domains and models, exceeding 30% in domains 2 and 5 for all models and exceeding 35% for the overall RoB conclusion.
- Mean top-1 BM25 retrieval scores were similar across models (approximately 30-31), suggesting hallucination differences were not primarily due to retrieval strength; sensitivity analyses showed evidence support increased with larger top-k retrieval depth (k=1, 3, 5).
Methods
- Retrospective evaluation using 97 randomized controlled trials from a 2023 Cochrane systematic review on mental health and well-being interventions, restricted to studies with complete RoB 2 data and accessible full-text PDFs; no train-validation split was applied.
- Three LLMs (GPT-5, OpenAI o3-mini, GPT-3.5 Turbo) generated structured RoB 2 signaling-question and domain-level judgments via schema-constrained prompts; outputs were compared with human RoB 2 annotations using exact and binary accuracy, sensitivity, specificity, F1-score, Youden J, Cohen κ, and Fleiss κ.
- For each generated claim, full-text reports were chunked (1400 characters, 200-character overlap) and retrieved with Okapi BM25 (top-k default 5); a constrained GPT-5 judge assigned verdicts of supported, contradicted, not found, or out of scope with verbatim quotations, yielding evidence support and conservative/strict hallucination rates. Embedding-based semantic similarity was used as a grounding diagnostic.
Limitations
- Stated: BM25 lexical matching may miss paraphrased or implicitly stated evidence; PDF extraction quality, chunking strategy, and top-k selection may affect retrieval; verification relied on a single LLM judge; the evaluation used one Cochrane review of 97 RCTs in mental health and well-being, limiting generalizability; RoB assessment is subject to variable reporting quality and interreviewer subjectivity; generator reasoning depth was only partially examined; poor-quality PDFs may elevate hallucination rates.
- Stated: prompt specifications were not validated on a separate held-out prompt development dataset.
- Evident from the text: the same model family (GPT-5) served as both one of the evaluated generators and the verification judge, which could introduce shared-model bias in verdicts; the study reports no multijudge adjudication or cross-domain validation.
Model-written summary. Check it against the paper before relying on it.
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Cites
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Claims the paper makes
44 of 49 cited sources checked · 25 supported · 2 flagged · accuracy not yet measured
- Premisecitation
LLMs can produce hallucinations, defined as generated outputs that are not supported by source materials.
“A growing body of literature indicates that LLMs can produce hallucinations, defined here as generated outputs that are not supported by source materials, raising concerns regarding information quality and safety in health care applications [7-12].”
Quote in the paperSubstantial claim6 of 6 sources checked- cites [7] source
- cites [8] source
- cites [9] source
- cites [10] source
- cites [11] source
- cites [12] source
The “Multimodal Hallucination” section defines hallucination as an MLLM response inconsistent with image content. This supports the core idea of output not grounded in its input, but the source does not establish the broader definition for LLMs generally or for source materials beyond images. (LLM, conf=0.84)
Experimental — accuracy not yet measured
- Premisecitation
Hallucination risks have been documented in acceptance or elaboration of fabricated clinical details embedded in prompts during clinical decision support.
“acceptance or elaboration of fabricated clinical details embedded in prompts during clinical decision support [11]”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites [11] source
- Premisecitation
AI-generated medical information may lack explicit support from source documents.
“AI-generated medical information may lack explicit support from source documents.”
Quote in the paperSubstantial claim6 of 6 sources checked- cites [7] source
- cites [8] source
- cites [9] source
The Methods (Systematic Review on LLMs: Paper Retrieval; page unavailable) describe AI-generated references that could be “unsupported by the available literature,” and the Discussion (Principal Findings; page unavailable) reports hallucinated references in systematic reviews. This supports the possibility of unsupported AI-generated references, but the study does not assess whether medical information or claims are explicitly supported by source documents. (LLM, conf=0.83)
Experimental — accuracy not yet measured - cites [10] source
The Introduction’s ‘Advent of Generative AI—Large Language Models in Health Care’ section says LLMs may generate plausible but incorrect content. It does not address whether AI-generated medical information is explicitly supported by source documents; searches for source-document support and grounding found no passage on that point. Page numbers were not available in our copy. (LLM, conf=0.70)
Experimental — accuracy not yet measured - cites [11] source
- cites [12] source
The “Multimodal Hallucination” section (page unavailable) says model-generated responses can be inconsistent with image content, supporting the general concern that AI output may be ungrounded. The “Scenario/task extension” section discusses medical image question answering, but the survey does not connect its hallucination discussion to medical information or to explicit support from source documents. (LLM, conf=0.82)
Experimental — accuracy not yet measured
- Premisecitation
Hallucination risks have been documented in fabricated or inaccurate references in systematic reviews.
“including fabricated or inaccurate references in systematic reviews [7,9]”
Quote in the paperNot a substantial claim2 of 2 sources checked- cites [7] source
The Introduction reports that AI chatbots generated citations that were fabricated or contained falsified bibliographic data. The paper does not place those references in systematic reviews; its Discussion describes reference hallucinations across chatbot outputs more generally. No page numbers are available in our copy. (LLM, conf=0.86)
Experimental — accuracy not yet measured - cites [9] source
- Premisecitation
Hallucination risks have been documented in unsupported statements in clinical text summarization.
“unsupported statements in clinical text summarization [8]”
Quote in the paperSubstantial claim1 of 1 sources checked- cites [8] source
- Premisecitation
LLMs have a tendency to generate fluent, plausible, and contextually appropriate outputs that nonetheless do not correspond to information explicitly present in source materials.
“This inconsistency reflects a known and well-documented limitation of LLMs: their tendency to generate fluent, plausible, and contextually appropriate outputs that nonetheless do not correspond to information explicitly present in source materials.”
Quote in the paperSubstantial claim4 of 4 sources checked- cites [7] source
The Introduction says chatbots generated detailed citations that seemed authentic but proved fabricated or erroneous when checked against medical literature. The Discussion (Principal Findings; page unavailable) also notes hallucinations in content as well as references. The paper supports the concern about plausible-looking inaccuracies, but its evidence focuses on citations; it does not establish the broader claim that LLM outputs fail to correspond to information explicitly present in source materials. (LLM, conf=0.82)
Experimental — accuracy not yet measured - cites [9] source
The Discussion’s Principal Findings (page not provided) report that ChatGPT and Bard generated plausible-looking references that were misleading or nonexistent, supporting the claim that LLM output can appear credible while being inaccurate. The study tested references produced for systematic reviews, however, not whether fluent outputs generally correspond to information explicitly present in source materials; the Strengths and Limitations section also cautions against generalizing beyond the models and subject area tested. (LLM, conf=0.84)
Experimental — accuracy not yet measured - cites [8] source
The Introduction (page unavailable) defines hallucinations as information generated by LLMs that is not present in the input data, supporting the claim’s central point. The Discussion (page unavailable) says LLMs can produce unfactual or unfaithful text with high confidence, but it does not establish that such outputs are fluent, plausible, and contextually appropriate. (LLM, conf=0.79)
Experimental — accuracy not yet measured - cites [11] source
- Findingown data
The strongest binary accuracy was in domains 1 and 5, where binary accuracy ranged from approximately 93% to 98%.
“with the strongest performance in domains 1 and 5, where binary accuracy ranged from approximately 93% to 98%.”
Quote in the paperNot a substantial claim - Findingown data
For GPT-5 in the adverse events domain, a lower mean BM25 score coincided with reduced evidence support.
“One exception was observed for GPT-5 in the adverse events domain, where a lower mean BM25 score coincided with reduced evidence support, suggesting possible underretrieval or weaker alignment between retrieved passages and generated claims in this domain.”
Quote in the paperNot a substantial claim - Findingown data
GPT-5 showed notably higher agreement on the overall RoB conclusion (linear κ=0.78; and quadratic κ=0.81) than OpenAI o3-mini and GPT-3.5 (linear κ approximately 0.42-0.44; and quadratic κ approximately 0.47-0.50).
“GPT-5 showed notably higher agreement on the overall RoB conclusion (linear κ=0.78; and quadratic κ=0.81) than OpenAI o3-mini and GPT-3.5 (linear κ approximately 0.42-0.44; and quadratic κ approximately 0.47-0.50).”
Quote in the paperSubstantial claim - Findingown data
Evidence support rates across models ranged from only 60% to 65%.
“evidence support rates across models ranged from only 60% to 65%”
Quote in the paperSubstantial claim- Rests on an assumption: The constrained judge LLM (GPT-5) verdicts accurately classify whether a generated claim is supported, contradicted, not found, or out of scope.
- Rests on an assumption: The top-k BM25 retrieved passages contain all evidence needed to verify each claim.
- Findingown data
Agreement was fair to moderate in domain 5 (linear κ approximately 0.36-0.43; and quadratic κ approximately 0.43-0.49).
“and fair to moderate in domain 5 (linear κ approximately 0.36-0.43; and quadratic κ approximately 0.43-0.49).”
Quote in the paperNot a substantial claim - Findingown data
Conservative hallucination rates were 34%-37%.
“with conservative hallucination rates of 34%-37%.”
Quote in the paperSubstantial claim- Rests on an assumption: The constrained judge LLM (GPT-5) verdicts accurately classify whether a generated claim is supported, contradicted, not found, or out of scope.
- Rests on an assumption: The top-k BM25 retrieved passages contain all evidence needed to verify each claim.
- Findingown data
GPT-5 achieved the lowest hallucination rates (conservative: mean 34.8%, SD 5.1%; strict: mean 35.7%, SD 5.9%).
“GPT-5 achieved the highest mean evidence support rate (mean 64.3%, SD 5.9%) and the lowest hallucination rates (conservative: mean 34.8%, SD 5.1%; and strict: mean 35.7%, SD 5.9%), closely followed by OpenAI o3-mini.”
Quote in the paperSubstantial claim - Findingown data
Across models, overall evidence support rates were approximately 60%-65%.
“As shown in Figure 3A, overall evidence support rates were approximately 60%-65% across models, whereas both conservative and strict hallucination rates ranged from approximately 35% to 37%.”
Quote in the paperSubstantial claim - Findingown data
Even items with confirmed documentary support showed low absolute similarity (max top-k≈0.49; mean top-k≈0.42).
“Critically, even items with confirmed documentary support showed low absolute similarity (max top-k≈0.49; mean top-k≈0.42), indicating that semantic similarity was not sufficient to distinguish supported from unsupported items.”
Quote in the paperSubstantial claim - Findingown data
GPT-5 showed the lowest strict hallucination rate (35.7%).
“and the lowest strict hallucination rate (35.7%).”
Quote in the paperNot a substantial claim- Rests on an assumption: The constrained judge LLM (GPT-5) verdicts accurately classify whether a generated claim is supported, contradicted, not found, or out of scope.
- Rests on an assumption: The top-k BM25 retrieved passages contain all evidence needed to verify each claim.
- Findingown data
The judge without reasoning classified a substantially larger proportion of items as "out of scope" rather than resolving them into supported or contradicted verdicts, resulting in higher strict hallucination rates overall.
“By contrast, the judge without reasoning classified a substantially larger proportion of items as “out of scope” rather than resolving them into supported or contradicted verdicts, resulting in higher strict hallucination rates overall.”
Quote in the paperSubstantial claim - Findingown data
Mean semantic similarity decreased monotonically from supported to contradicted, not found, and out-of-scope verdicts.
“Mean similarity decreased monotonically from supported to contradicted, not found, and out-of-scope verdicts, but the difference between supported and nonsupported items was small (max top-k: Mann-Whitney z=20.14, P<.001, rank-biserial r=0.17; medians 0.49 vs 0.46).”
Quote in the paperSubstantial claim - Findingown data
Large gaps persisted even in domains with high binary accuracy, particularly domains 2 and 5, where gaps exceeded 30% for all models.
“Notably, large gaps persisted even in domains with high binary accuracy, particularly domains 2 and 5, where gaps exceeded 30% for all models.”
Quote in the paperSubstantial claim - Findingown data
Mean top-1 BM25 scores clustered near 31 across GPT-5, OpenAI o3-mini, and GPT-3.5, with overlapping 95% CIs.
“Mean top-1 BM25 scores (Figure 3B) clustered near 31 across GPT-5, OpenAI o3-mini, and GPT-3.5, with overlapping 95% CIs.”
Quote in the paperSubstantial claim - Findingown data
GPT-5 showed the highest mean evidence support (64.3%).
“GPT-5 showed the highest mean evidence support (64.3%)”
Quote in the paperNot a substantial claim- Rests on an assumption: The constrained judge LLM (GPT-5) verdicts accurately classify whether a generated claim is supported, contradicted, not found, or out of scope.
- Rests on an assumption: The top-k BM25 retrieved passages contain all evidence needed to verify each claim.
- Findingown data
Semantic similarity correlated only weakly with the BM25 top-1 score (Spearman ρ=0.22, P<.001).
“Semantic similarity also correlated only weakly with the BM25 top-1 score (Spearman ρ=0.22, P<.001), indicating that lexical and embedding metrics capture complementary rather than redundant dimensions of grounding.”
Quote in the paperSubstantial claim - Findingown data
Of the 113 randomized trials included in the review, 97 (85.8%) had complete RoB data and accessible full-text reports in PDF.
“Of the 113 randomized trials included in the review, analyses were restricted to 97 (85.8%) studies with complete RoB data and accessible full-text reports in PDF.”
Quote in the paperNot a substantial claim - Findingown data
Restricting context to a single passage (k=1) resulted in markedly elevated hallucination rates.
“Conversely, restricting context to a single passage (k=1) resulted in markedly elevated hallucination rates, reflecting the difficulty of grounding judgments using minimal evidence.”
Quote in the paperSubstantial claim - Findingown data
Semantic similarity scores were uniformly low across all models and topics.
“Semantic similarity scores were uniformly low across all models and topics.”
Quote in the paperSubstantial claim - Findingown data
All 3 models demonstrated high binary accuracy across domains.
“all 3 models demonstrated high binary accuracy across domains”
Quote in the paperSubstantial claim - Findingown data
Both conservative and strict hallucination rates ranged from approximately 35% to 37% across models.
“As shown in Figure 3A, overall evidence support rates were approximately 60%-65% across models, whereas both conservative and strict hallucination rates ranged from approximately 35% to 37%.”
Quote in the paperSubstantial claim - Findingown data
Agreement was lower in domain 4, where κ values were in the fair range (linear κ approximately 0.27-0.31; and quadratic κ approximately 0.25-0.29).
“Agreement was lower in domain 4, where κ values were in the fair range (linear κ approximately 0.27-0.31; and quadratic κ approximately 0.25-0.29)”
Quote in the paperNot a substantial claim - Findingown data
GPT-5 showed the strongest overall task performance.
“GPT-5 showed the strongest overall task performance.”
Quote in the paperSubstantial claim - Findingown data
OpenAI o3-mini achieved the highest support for adverse events (76.79%).
“OpenAI o3-mini performed competitively across most domains and achieved the highest support for adverse events (76.79%); however, this estimate was based on a single study and should therefore be interpreted with caution.”
Quote in the paperNot a substantial claim - Findingown data
Exact (ordinal) accuracy was substantially lower across domains, indicating frequent mismatches in severity classification despite broad agreement on overall risk direction.
“By contrast, exact (ordinal) accuracy was substantially lower across domains, indicating frequent mismatches in severity classification despite broad agreement on overall risk direction.”
Quote in the paperSubstantial claim - Findingown data
GPT-5 achieved the highest mean evidence support rate (mean 64.3%, SD 5.9%).
“GPT-5 achieved the highest mean evidence support rate (mean 64.3%, SD 5.9%) and the lowest hallucination rates (conservative: mean 34.8%, SD 5.1%; and strict: mean 35.7%, SD 5.9%), closely followed by OpenAI o3-mini.”
Quote in the paperSubstantial claim - Findingown data
Binary accuracy of AI-generated RoB judgments was high across all domains (90%-98%).
“Binary accuracy of AI-generated RoB judgments was high across all domains (90%-98%), whereas evidence support rates clustered at only 60%-65%.”
Quote in the paperSubstantial claim - Findingown data
The difference in semantic similarity between supported and nonsupported items was small (max top-k: Mann-Whitney z=20.14, P<.001, rank-biserial r=0.17; medians 0.49 vs 0.46).
“Mean similarity decreased monotonically from supported to contradicted, not found, and out-of-scope verdicts, but the difference between supported and nonsupported items was small (max top-k: Mann-Whitney z=20.14, P<.001, rank-biserial r=0.17; medians 0.49 vs 0.46).”
Quote in the paperSubstantial claim - Findingown data
Mean top-1 BM25 retrieval scores were similar across models (approximately 30-31).
“Mean top-1 BM25 retrieval scores were similar across models (approximately 30-31)”
Quote in the paperSubstantial claim - Findingown data
GPT-3.5 demonstrated lower performance on both measures across all domains.
“while GPT-3.5 demonstrated lower performance on both measures across all domains.”
Quote in the paperNot a substantial claim - Findingown data
The accuracy-support gap (binary accuracy minus evidence support) ranged from 11% to 37% across domains and models.
“The accuracy-support gap (binary accuracy minus evidence support) ranged from 11% to 37% across domains and models (Table 1).”
Quote in the paperSubstantial claim - Findingown data
Exact accuracy was substantially lower than binary accuracy (42%-71%).
“Furthermore, conservative hallucination rates remained substantial at approximately 35%-37%, and exact accuracy was substantially lower than binary accuracy (42%-71%).”
Quote in the paperSubstantial claim - Findingown data
External agreement with human ratings was substantial in domains 1-3, with linear κ values ranging from approximately 0.64 to 0.71 and quadratic κ values from approximately 0.72 to 0.81.
“External agreement with human ratings was substantial in domains 1-3, with linear κ values ranging from approximately 0.64 to 0.71 and quadratic κ values from approximately 0.72 to 0.81.”
Quote in the paperSubstantial claim - Interpretationreasoning
Agreement with human labels does not guarantee that AI-generated medical information can be transparently traced back to authoritative source documents.
“agreement with human labels does not guarantee that AI-generated medical information can be transparently traced back to authoritative source documents.”
Quote in the paperSubstantial claim - Premisereasoning
Existing evaluations of AI-generated medical information often rely on agreement with human judgments and do not directly assess whether AI-generated content is grounded in underlying evidence.
“existing evaluations often rely on agreement with human judgments and do not directly assess whether AI-generated content is grounded in underlying evidence.”
- Also stated in: § Introduction · plain
“most evaluations of hallucination in AI-generated health information rely on indirect measures such as agreement with human judgments, task-level accuracy, or expert preference ratings.”
Quote in the paperSubstantial claim - Also stated in: § Introduction · plain
- Premisereasoning
Outputs that appear correct may still lack support from source documents, particularly when models infer intent, assumptions, or methodological details that are not explicitly reported.
“outputs that appear correct may still lack support from source documents, particularly when models infer intent, assumptions, or methodological details that are not explicitly reported.”
Quote in the paperSubstantial claim - Premisereasoning
The RoB 2 process continues to require detailed evidence collection and justification, limiting scalability in digital evidence synthesis workflows.
“the process continues to require detailed evidence collection and justification, limiting scalability in digital evidence synthesis workflows.”
Quote in the paperSubstantial claim - Interpretationown data
Verdict reliability may be sensitive to the reasoning depth of the judge LLM, in addition to retrieval quality.
“This has practical implications for RtV pipeline design, suggesting that verdict reliability may be sensitive to the reasoning depth of the judge LLM, in addition to retrieval quality.”
Quote in the paperSubstantial claim - Interpretationown data
Evidence grounding is sensitive to retrieval quality when relevant signals are sparse or heterogeneously reported.
“This finding highlights the sensitivity of evidence grounding to retrieval quality when relevant signals are sparse or heterogeneously reported.”
Quote in the paperSubstantial claim - Interpretationown data
High decision-level accuracy and strong agreement with human judgments do not guarantee evidence grounding.
“The principal finding is that high decision-level accuracy and strong agreement with human judgments do not guarantee evidence grounding.”
Quote in the paperSubstantial claim - Interpretationown data
Weaker semantic grounding may contribute secondarily, particularly among not found and out-of-scope items.
“The pervasively low similarity is consistent with systematic divergence between the model’s rationale phrasing and the source text, while the modest verdict gradient suggests that weaker semantic grounding may contribute secondarily, particularly among not found and out-of-scope items.”
Quote in the paperNot a substantial claim - Interpretationown data
Semantic similarity was not sufficient to distinguish supported from unsupported items.
“Critically, even items with confirmed documentary support showed low absolute similarity (max top-k≈0.49; mean top-k≈0.42), indicating that semantic similarity was not sufficient to distinguish supported from unsupported items.”
Quote in the paperSubstantial claim - Interpretationown data
Incorporating evidence support revealed a substantial divergence between apparent decision-level correctness and documentary grounding.
“Incorporating evidence support revealed a substantial divergence between apparent decision-level correctness and documentary grounding.”
Quote in the paperSubstantial claim - Interpretationown data
Observed differences in evidence support likely reflect downstream reasoning and claim formulation rather than systematic differences in retrieval strength.
“The observed differences in evidence support therefore likely reflect downstream reasoning and claim formulation rather than systematic differences in retrieval strength.”
Quote in the paperSubstantial claim - Interpretationown data
The k=1 result reflects the difficulty of grounding judgments using minimal evidence.
“Conversely, restricting context to a single passage (k=1) resulted in markedly elevated hallucination rates, reflecting the difficulty of grounding judgments using minimal evidence.”
Quote in the paperSubstantial claim - Interpretationreasoning
The RtV framework provides a reproducible, source-linked evaluation paradigm that captures a clinically and informatically important dimension of model reliability not captured by conventional accuracy and agreement metrics.
“By reframing hallucination as a problem of evidence grounding rather than disagreement with human judgments, the RtV framework provides a reproducible, source-linked evaluation paradigm that captures a clinically and informatically important dimension of model reliability that is not captured by conventional accuracy and agreement metrics.”
Quote in the paperSubstantial claim - Study design and conductown data
The 76.79% support estimate for OpenAI o3-mini on adverse events was based on a single study.
“OpenAI o3-mini performed competitively across most domains and achieved the highest support for adverse events (76.79%); however, this estimate was based on a single study and should therefore be interpreted with caution.”
Quote in the paperNot a substantial claim - Interpretationown data
The pervasively low similarity is consistent with systematic divergence between the model's rationale phrasing and the source text.
“The pervasively low similarity is consistent with systematic divergence between the model’s rationale phrasing and the source text, while the modest verdict gradient suggests that weaker semantic grounding may contribute secondarily, particularly among not found and out-of-scope items.”
Quote in the paperSubstantial claim - Interpretationown data
A substantial proportion of AI-generated judgments lacked explicit documentary support even when they aligned with human assessments at the decision level.
“These findings indicate that a substantial proportion of AI-generated judgments lacked explicit documentary support, even when they aligned with human assessments at the decision level.”
Quote in the paperSubstantial claim - Interpretationown data
The RtV framework is feasible for routine integration into evidence-focused workflows.
“From an application perspective, the RtV framework is feasible for routine integration into evidence-focused workflows.”
Quote in the paperSubstantial claim - Interpretationown data
Richer retrieval context substantially increased the availability of documentary support for generated claims.
“This pattern was consistent across topics, indicating that richer retrieval context substantially increased the availability of documentary support for generated claims.”
Quote in the paperSubstantial claim - Interpretationown data
Measuring evidence support and hallucination reveals important limitations that are not captured by agreement metrics alone.
“Measuring evidence support and hallucination reveals important limitations that are not captured by agreement metrics alone.”
Quote in the paperSubstantial claim- Rests on an assumption: The constrained judge LLM (GPT-5) verdicts accurately classify whether a generated claim is supported, contradicted, not found, or out of scope.
- Rests on an assumption: The top-k BM25 retrieved passages contain all evidence needed to verify each claim.
- Interpretationown data
Differences in evidence support were not primarily driven by differences in retrieval strength.
“Retrieval diagnostics suggested that differences in evidence support were not primarily driven by differences in retrieval strength.”
Quote in the paperSubstantial claim - Interpretationown data
Judge model reasoning capacity influences verdict discrimination in the RtV framework.
“These findings suggest that judge model reasoning capacity influences verdict discrimination in the RtV framework: reasoning-capable models may be better able to interpret ambiguous retrieval contexts and render substantive evidence judgments, whereas models without explicit reasoning may be more likely to abstain when evidence is indirect or incomplete.”
Quote in the paperSubstantial claim - Study design and conductreasoning
The retrieval component relied on BM25 lexical matching, which may miss paraphrased, implicitly stated, or semantically equivalent evidence not captured by term overlap.
“A limitation of this study is that the retrieval component relied on BM25 lexical matching, which may miss paraphrased, implicitly stated, or semantically equivalent evidence not captured by term overlap.”
Quote in the paperNot a substantial claim - Interpretationown data
AI-generated medical information can achieve high decision-level accuracy while still lacking documentary support in a substantial proportion of outputs.
“AI-generated medical information can achieve high decision-level accuracy while still lacking documentary support in a substantial proportion of outputs.”
Quote in the paperSubstantial claim- Rests on an assumption: The constrained judge LLM (GPT-5) verdicts accurately classify whether a generated claim is supported, contradicted, not found, or out of scope.
- Rests on an assumption: The top-k BM25 retrieved passages contain all evidence needed to verify each claim.
- Study design and conductnone given
The empirical evaluation was conducted using a single Cochrane systematic review on mental health and well-being interventions, comprising 97 randomized controlled trials.
“The empirical evaluation was conducted using a single Cochrane systematic review on mental health and well-being interventions, comprising 97 randomized controlled trials.”
Quote in the paperSubstantial claim - Interpretationown data
Task structure influenced evidence grounding.
“Domain-level patterns further indicated that task structure influenced evidence grounding.”
Quote in the paperNot a substantial claim - Interpretationown data
Differences in hallucination were not primarily attributable to differences in retrieval strength.
“suggesting that differences in hallucination were not primarily attributable to differences in retrieval strength.”
Quote in the paperSubstantial claim- Rests on an assumption: The constrained judge LLM (GPT-5) verdicts accurately classify whether a generated claim is supported, contradicted, not found, or out of scope.
- Rests on an assumption: The top-k BM25 retrieved passages contain all evidence needed to verify each claim.
- Interpretationown data
Lexical and embedding metrics capture complementary rather than redundant dimensions of grounding.
“Semantic similarity also correlated only weakly with the BM25 top-1 score (Spearman ρ=0.22, P<.001), indicating that lexical and embedding metrics capture complementary rather than redundant dimensions of grounding.”
Quote in the paperSubstantial claim - Interpretationown data
Accuracy and evidence support are empirically dissociable.
“A crucial finding of this study is that accuracy and evidence support are empirically dissociable.”
Quote in the paperSubstantial claim - Interpretationreasoning
The similar BM25 scores suggest comparable access to potentially relevant evidence across models.
“As BM25 scores reflect lexical relevance between queries and retrieved passages, these similar values suggest comparable access to potentially relevant evidence across models.”
Quote in the paperSubstantial claim- Rests on an assumption: BM25 top-1 score reflects retrieval strength or access to relevant evidence.
- Classified as probably not a substantial claim. 33
- May combine two claims. 38
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationRose et al found moderate to substantial interrater agreement between ChatGPT-4o and human reviewers across Cochrane RoB review domains.
“For example, Lai et al [18,27] demonstrated that LLMs can perform RoB assessments at a level comparable to trained reviewers in structured appraisal tasks, and Rose et al [25,26] found moderate to substantial interrater agreement between ChatGPT-4o and human reviewers across Cochrane RoB review domains.”
Quote in the paperNot a substantial claim2 of 2 sources checked- cites [25] source
The Abstract (Results) describes agreement as an outcome the authors will report, not a finding. The Methods (Outcomes) explicitly says they will not assess agreement across Cochrane RoB domains, instead focusing on overall risk of bias. No page numbers are provided in our copy. (LLM, conf=0.90)
Checked by a reasoning model — may be wrong.
Experimental — accuracy not yet measured - cites [26] source
Table 4 reports human–ChatGPT-4o agreement of 50.7% for overall RoB and 78.7% for RoB due to randomization. But its Cohen’s κ values are 0.215 (classified as fair by the paper’s criteria) and 0.537 (moderate), not moderate to substantial. The Discussion’s Strengths and Limitations section explicitly says the study did not assess other domains, so the claim overextends the finding across Cochrane RoB domains. (LLM, conf=0.91)
Experimental — accuracy not yet measured
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationRecent studies have reported promising agreement between LLMs and human reviewers for RoB assessment.
“Recent studies have examined the ability of LLMs to assist with RoB assessment and have reported promising agreement with human reviewers [18,24-27].”
Quote in the paperNot a substantial claim4 of 5 sources checked- cites [18] source
- cites [24] source
- cites [25] source
The Abstract Conclusions (page unavailable) say the proposed study is likely to provide the first evidence of agreement between human and LLM risk-of-bias assessments. The Background (page unavailable) says the authors were unaware of research assessing agreement in overall risk-of-bias judgments. This protocol therefore does not report the promising agreement attributed to it. (LLM, conf=0.89)
Checked by a reasoning model — may be wrong.
Experimental — accuracy not yet measured - cites [26] source
- cites [27] source
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
PremisecitationRecent studies have explored the use of LLMs to assist with evidence appraisal tasks, including RoB assessment, and have reported promising agreement with human judgments.
“Recent studies have explored the use of LLMs to assist with evidence appraisal tasks, including RoB assessment, and have reported promising agreement with human judgments [18].”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites [18] source
May combine two claims.
PremisecitationHuman RoB assessments in the source Cochrane review were performed independently by 2 reviewers using the RoB 2 tool, with discrepancies resolved through consensus discussion.
“In accordance with standard Cochrane methodology, RoB assessments in the source review were performed independently by 2 reviewers using the RoB 2 tool, with discrepancies resolved through consensus discussion; full reviewer details are reported in the source review [19].”
Quote in the paperSubstantial claim1 of 1 sources checked- cites [19] source
The Methods (Data collection and analysis) state that two review authors (EP and CC) independently assessed risk of bias using the Cochrane Risk of Bias 2 tool. They resolved disagreements by discussion or consultation with a third review author, so the claim's description of resolution solely through consensus discussion omits an alternative the source reports. (LLM, conf=0.85)
Experimental — accuracy not yet measured
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationLLMs have demonstrated strong performance across a wide range of biomedical knowledge and reasoning tasks.
“LLMs have demonstrated strong performance across a wide range of biomedical knowledge and reasoning tasks, accelerating their adoption in health care workflows [1-6].”
Quote in the paperNot a substantial claim5 of 6 sources checked- cites [1] source
- cites [2] source
The Results (Emerging Trends; page unavailable) describe strong results on medical question answering and several biomedical NLP tasks, supporting examples of performance across different tasks. The Discussion (Prompt Engineering Techniques Effectiveness in Medical Research; page unavailable) cautions that results are not systematically in favor of LLM-based methods, so the unqualified claim of strong performance across a wide range overstates the review. The cited passages also do not establish that performance accelerated adoption in health care workflows. (LLM, conf=0.86)
Experimental — accuracy not yet measured - cites [3] source
The Discussion reports strong performance on theoretical, clinical, and integrated questions in a bilingual nuclear medicine exam, but the Conclusion also reports 0% accuracy on medical legal regulation questions. This supports performance on several biomedical knowledge and reasoning tasks, not a wide range of tasks generally; the cited passages also do not establish accelerated adoption in health care workflows. (LLM, conf=0.84)
Experimental — accuracy not yet measured - cites [4] source
The Abstract and Discussion report strong Med-PaLM 2 performance across medical knowledge benchmarks, long-form answers, and bedside consultation questions. The Discussion says validation in real-world workflows remains future work; it does not establish that this performance has accelerated adoption in health care workflows. (LLM, conf=0.85)
Experimental — accuracy not yet measured - cites [5] source
- cites [6] source
The Introduction (page unavailable) describes LLMs as powerful NLP tools across different tasks, and the Conclusion reports promising results for literature-review automation. The paper does not establish strong performance across a wide range of biomedical knowledge and reasoning tasks or show that such performance accelerated adoption in health care workflows. (LLM, conf=0.83)
Experimental — accuracy not yet measured
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
PremisecitationConceptual and sociotechnical analyses suggest that naive reliance on AI-generated medical information may amplify automation bias, erode professional expertise, and reinforce self-referential learning loops in digital health systems.
“Conceptual and sociotechnical analyses further suggest that naive reliance on AI-generated medical information may amplify automation bias, erode professional expertise, and reinforce self-referential learning loops in digital health systems [10].”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites [10] source
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationThe revised RoB 2 tool introduced outcome-specific domains, signaling questions, and explicit decision rules to improve consistency.
“Although the revised RoB 2 tool introduced outcome-specific domains, signaling questions, and explicit decision rules to improve consistency [17]”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites [17] source
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationReviewers were systematic review specialists with expertise in global mental health interventions.
“Reviewers were systematic review specialists with expertise in global mental health interventions; their institutional affiliations and authorship details are listed in the source review [19].”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites [19] source
The Methods > Data collection and analysis section identifies review authors conducting systematic screening, risk-of-bias assessment, and GRADE assessment for this review of mental-health interventions in low- and middle-income countries. This supports describing them as reviewers working in that field. The available copy does not show their institutional affiliations or establish that all were systematic review specialists; its end may be missing. (LLM, conf=0.78)
Experimental — accuracy not yet measured
May combine two claims.
PremisecitationRoB assessment has long been recognized as labor intensive, variably reproducible, and prone to misapplication in specific domains such as selective reporting.
“However, RoB assessment has long been recognized as labor intensive, variably reproducible, and prone to misapplication in specific domains such as selective reporting [14-16].”
Quote in the paperSubstantial claim1 of 3 sources checked- cites [14] source
- cites [15] source
The Results (Table 2; page unavailable in our copy) show poor agreement between reviewer groups for selective reporting (κ = 0.13), and the Discussion says RoB assessments may not be reproducible across groups. The paper describes intensive reviewer training, but does not establish that RoB assessment itself is labor intensive. Poor agreement in the selective-reporting domain does not, on its own, establish misapplication. (LLM, conf=0.84)
Experimental — accuracy not yet measured - cites [16] source
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationThe Cochrane risk-of-bias (RoB) assessment tool formalized a structured, domain-based approach to judgments anchored in trial methodology rather than undifferentiated quality scores.
“Within systematic reviews, the Cochrane risk-of-bias (RoB) assessment tool formalized a structured, domain-based approach to judgments anchored in trial methodology rather than undifferentiated quality scores [13].”
Quote in the paperNot a substantial claim1 of 1 sources checked- cites [13] source
May combine two claims.
PremisecitationPrior work has found hallucinations in several relevant domains, including fabricated or inaccurate references in systematic reviews, unsupported claims in clinical text summarization, and adversarial exploitation of false clinical details in decision support systems.
“Prior work has found hallucinations in several relevant domains, including fabricated or inaccurate references in systematic reviews [7,9], unsupported claims in clinical text summarization [8], and adversarial exploitation of false clinical details in decision support systems [11].”
Quote in the paperNot a substantial claim4 of 4 sources checked- cites [7] source
The Results report inaccurate or hallucinated references generated by medical AI chatbots, supporting the reference-error portion of the claim. The Methods (Medical Prompts) say the chatbots were asked about medical topics and clinical scenarios, not to produce systematic reviews; this source does not establish the systematic-review setting. The other two domains in the citing sentence are attached to different citations. (LLM, conf=0.85)
Experimental — accuracy not yet measured - cites [9] source
- cites [8] source
- cites [11] source
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationLai et al demonstrated that LLMs can perform RoB assessments at a level comparable to trained reviewers in structured appraisal tasks.
“For example, Lai et al [18,27] demonstrated that LLMs can perform RoB assessments at a level comparable to trained reviewers in structured appraisal tasks, and Rose et al [25,26] found moderate to substantial interrater agreement between ChatGPT-4o and human reviewers across Cochrane RoB review domains.”
Quote in the paperNot a substantial claim2 of 2 sources checkedMay combine two claims.
Findingown dataGPT-5 attained the highest exact accuracy in most RoB 2 assessment domains, including 0.64 in domain 1, 0.54-0.71 in domains 2 and 3, and 0.42-0.45 in domains 4 and 5.
“and attained the highest exact accuracy in most RoB 2 assessment domains, including 0.64 in domain 1, 0.54-0.71 in domains 2 and 3, and 0.42-0.45 in domains 4 and 5.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataGPT-3.5 showed modestly lower evidence support and higher hallucination rates across all 3 measures.
“GPT-3.5 showed modestly lower evidence support and higher hallucination rates across all 3 measures.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataEvidence support rates increased substantially and consistently with larger k across all 8 topics, while conservative and strict hallucination rates decreased correspondingly.
“As shown in Figure 4, evidence support rates increased substantially and consistently with larger k across all 8 topics, while conservative and strict hallucination rates decreased correspondingly.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataRtV required end-to-end runtimes of 50-158 seconds per study, depending on model choice, and the computational requirements were modest.
“It required end-to-end runtimes of 50-158 seconds per study, depending on model choice, and the computational requirements were modest.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataOpenAI o3-mini closely tracked GPT-5 on binary accuracy but consistently showed lower exact accuracy.
“OpenAI o3-mini closely tracked GPT-5 on binary accuracy but consistently showed lower exact accuracy”
Quote in the paperNot a substantial claimMay combine two claims.
FindingreasoningAI-generated RoB judgments frequently agreed with human judgments while simultaneously lacking evidence grounding in the original trial reports.
“AI-generated RoB judgments frequently agreed with human judgments while simultaneously lacking evidence grounding in the original trial reports.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Findingnone givenThe included trials were published between 1996 and 2022.
“The included trials were published between 1996 and 2022.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataThe reasoning-capable judge assigned higher evidence support rates across most topics and produced more decisive conservative hallucination classifications.
“The reasoning-capable judge assigned higher evidence support rates across most topics and produced more decisive conservative hallucination classifications.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataLower reasoning depth in the generator model reduced both evidence support (65.5% to 55.9% pooled) and binary accuracy (89.5% to 77.7% pooled), without a comparable change in retrieval scores.
“Lower reasoning depth in the generator model reduced both evidence support (65.5% to 55.9% pooled) and binary accuracy (89.5% to 77.7% pooled), without a comparable change in retrieval scores.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataAcross domains, quadratic κ values consistently exceeded linear κ values, indicating that most disagreements involved adjacent categories on the ordinal RoB 2 scale rather than large category gaps.
“Across domains, quadratic κ values consistently exceeded linear κ values, indicating that most disagreements involved adjacent categories on the ordinal RoB 2 scale rather than large category gaps.”
Quote in the paperNot a substantial claimMay combine two claims.
Findingown dataFor the overall RoB conclusion, gaps exceeded 35% across models, indicating that many apparently correct judgments were not explicitly supported by the trial reports.
“For the overall RoB conclusion, gaps exceeded 35% across models, indicating that many apparently correct judgments were not explicitly supported by the trial reports.”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataGPT-5 achieved perfect performance on the overall RoB conclusion, with accuracy, sensitivity, specificity, F1-score, and Youden J all of 1.00.
“It achieved perfect performance on the overall RoB conclusion, with accuracy, sensitivity, specificity, F1-score, and Youden J all of 1.00”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataInternal consistency across models was strong in domain 1 (Fleiss κ=0.83) and domain 2 (Fleiss κ=0.86), and moderate in domains 3-5 (Fleiss κ of approximately 0.49-0.60) and for the overall RoB conclusion (Fleiss κ=0.51).
“Internal consistency across models was strong in domain 1 (Fleiss κ=0.83) and domain 2 (Fleiss κ=0.86), and moderate in domains 3-5 (Fleiss κ of approximately 0.49-0.60) and for the overall RoB conclusion (Fleiss κ=0.51).”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataMean support rate across RoB 2 domains was higher in domain 1 (approximately 0.78-0.80) and lower in domain 3 (approximately 0.56-0.59) across models.
“Radar plots of mean support rate across RoB 2 domains (Figure 3C) showed higher evidence support in domain 1 (approximately 0.78-0.80) and lower support in domain 3 (approximately 0.56-0.59) across models, potentially reflecting differences in reporting clarity and methodological complexity.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Findingown dataAssessments covered 7 outcome categories: diagnosis of mental disorders, quality of life, adverse events, psychological functioning and impairment, depressive symptoms, anxiety symptoms, and distress or posttraumatic stress disorder symptoms.
“Assessments covered 7 outcome categories: diagnosis of mental disorders, quality of life, adverse events, psychological functioning and impairment, depressive symptoms, anxiety symptoms, and distress or posttraumatic stress disorder symptoms.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim. May combine two claims.
InterpretationreasoningHallucination reflects a general and high-stakes failure mode of AI-generated medical information in digital health systems, where plausible statements lack documentary support but may nonetheless influence downstream decisions.
“In this sense, hallucination reflects a general and high-stakes failure mode of AI-generated medical information in digital health systems, where plausible statements lack documentary support but may nonetheless influence downstream decisions.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S4 (based).
Premisenone givenMost evaluations of hallucination in AI-generated health information rely on indirect measures such as agreement with human judgments, task-level accuracy, or expert preference ratings.
“Despite growing recognition of these risks, most evaluations of hallucination in AI-generated health information rely on indirect measures such as agreement with human judgments, task-level accuracy, or expert preference ratings.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S4 (based).
Interpretationnone givenThe proposed approach provides reproducible, source-linked quality metrics that are directly relevant to digital health applications.
“The proposed approach provides reproducible, source-linked quality metrics that are directly relevant to digital health applications.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim. May combine two claims.
InterpretationreasoningThe proposed evaluation approach is model-agnostic and task-general.
“While RoB assessment provides a concrete and well-defined test case, the proposed evaluation approach is model-agnostic and task-general.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductown dataGeneralizability to other clinical specialties, review types, or evidence appraisal frameworks has not been established.
“Generalizability to other clinical specialties, review types, or evidence appraisal frameworks has not been established and represents an important direction for future work.”
Quote in the paperNot a substantial claimMay combine two claims.
Interpretationown dataAI-generated medical information can achieve high decision-level accuracy while a substantial proportion of outputs remain unsupported by the source documents underlying the judgments.
“This study reveals that AI-generated medical information can achieve high decision-level accuracy while a substantial proportion of outputs remain unsupported by the source documents underlying the judgments.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).
Interpretationown dataThe domain-level pattern potentially reflects differences in reporting clarity and methodological complexity.
“Radar plots of mean support rate across RoB 2 domains (Figure 3C) showed higher evidence support in domain 1 (approximately 0.78-0.80) and lower support in domain 3 (approximately 0.56-0.59) across models, potentially reflecting differences in reporting clarity and methodological complexity.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim.
Study design and conductreasoningThe embedding-based semantic grounding diagnostic directly evaluates whether the model's stated rationale is semantically close to the retrieved trial text, including when the supporting evidence is paraphrased rather than lexically matched.
“This directly evaluates whether the model’s stated rationale is semantically close to the retrieved trial text, including when the supporting evidence is paraphrased rather than lexically matched.”
Quote in the paperSubstantial claimMay combine two claims.
PremisereasoningAgreement metrics summarize alignment with human judgments but do not assess whether model rationales are supported by the source documents.
“While these metrics summarize alignment with human judgments, they do not assess whether model rationales are supported by the source documents.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductnone givenPrompt adequacy was verified through iterative review against the instrument's signaling questions and decision rules before full-scale application across all 97 studies.
“Prompt adequacy was verified through iterative review against the instrument’s signaling questions and decision rules before full-scale application across all 97 studies.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim.
Study design and conductnone givenThe RtV procedure operationalizes hallucination assessment by explicitly separating information retrieval from claim verification.
“The RtV procedure operationalizes hallucination assessment by explicitly separating information retrieval from claim verification.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim. May combine two claims.
Study design and conductreasoningThe constrained design minimized variability associated with free-text generation and ensured consistency across models and studies.
“This constrained design minimized variability associated with free-text generation and ensured consistency across models and studies.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim.
Study design and conductreasoningThis design enables a distinction between failures of evidence access and failures of model reasoning.
“This design enables a distinction between failures of evidence access and failures of model reasoning.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Study design and conductnone givenPrompt specifications were developed based on the structure and decision logic of the Cochrane RoB 2 instrument and were not validated on a separate held-out prompt development dataset.
“Prompt specifications were developed based on the structure and decision logic of the Cochrane RoB 2 instrument [20] and were not validated on a separate held-out prompt development dataset.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [20] RoB 2: revised Cochrane risk-of-bias tool for randomized trialsCochrane20252026-05-04https://methods.cochrane.org/bias/resources/rob-2-revised-cochrane-risk-bias-tool-randomized-trials
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
May combine two claims.
Interpretationown dataThe divergence among binary accuracy, exact accuracy, and evidence support highlights a key limitation of agreement-based evaluation and underscores the importance of assessing whether AI-generated judgments are grounded in source documents.
“The divergence among binary accuracy, exact accuracy, and evidence support highlights a key limitation of agreement-based evaluation and underscores the importance of assessing whether AI-generated judgments are grounded in source documents.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductnone givenVerification relied on a single LLM judge, which may introduce systematic bias in borderline or ambiguous cases.
“Verification relied on a single LLM judge, which may introduce systematic bias in borderline or ambiguous cases; multijudge adjudication or ensemble verification approaches could reduce this risk, albeit at the cost of increased runtime.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim. May combine two claims.
Study design and conductreasoningThe structured output enabled consistent mapping to analytic variables, automated calculation of performance metrics, and traceability for adjudication.
“This structure enabled consistent mapping to analytic variables, automated calculation of performance metrics, and traceability for adjudication.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim.
Study design and conductown dataEach verification response included a verbatim quotation drawn from the retrieved trial text that grounds the judgment, making the evidentiary basis for each item-level decision directly traceable without requiring downstream re-derivation.
“Each response also included the verdict label, a verbatim quotation drawn from the retrieved trial text that grounds the judgment, and a 1-sentence rationale, making the evidentiary basis for each item-level decision directly traceable without requiring downstream re-derivation.”
Quote in the paperSubstantial claim- Rests on an assumption: The constrained judge LLM (GPT-5) verdicts accurately classify whether a generated claim is supported, contradicted, not found, or out of scope.
May combine two claims.
Interpretationown dataAgreement and evidence grounding capture different aspects of model reliability, and high agreement does not imply that generated claims are traceable to source documents.
“Our study addresses this gap by demonstrating that agreement and evidence grounding capture different aspects of model reliability, and that high agreement does not imply that generated claims are traceable to source documents.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim. May combine two claims.
Interpretationnone givenHigher semantic similarity indicates stronger semantic grounding of the explanation in the retrieved evidence, whereas low similarity across retrieved snippets indicates weak grounding and potential hallucination risk.
“Higher semantic similarity indicates stronger semantic grounding of the explanation in the retrieved evidence, whereas low similarity across retrieved snippets indicates weak grounding and potential hallucination risk.”
Quote in the paperSubstantial claim- Rests on an assumption: The top-k BM25 retrieved passages contain all evidence needed to verify each claim.
May combine two claims.
Interpretationown dataGPT-5 offered the most favorable balance between evidence support and hallucination control, with OpenAI o3-mini remaining closely comparable and GPT-3.5 exhibiting the highest tendency toward unsupported claims.
“In summary, GPT-5 offered the most favorable balance between evidence support and hallucination control, with OpenAI o3-mini remaining closely comparable and GPT-3.5 exhibiting the highest tendency toward unsupported claims.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductnone givenRetrieval parameters were applied consistently across all 97 studies and all 3 LLMs.
“These parameters were applied consistently across all 97 studies and all 3 LLMs.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim.
InterpretationreasoningThe resulting evidence support and hallucination metrics complement conventional accuracy and agreement measures by directly assessing whether AI-generated medical information is grounded in source documents.
“The resulting evidence support and hallucination metrics complement conventional accuracy and agreement measures by directly assessing whether AI-generated medical information is grounded in source documents.”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationown dataThis pattern suggests high convergence in domains governed by explicit methodological criteria and greater divergence in domains requiring more nuanced interpretation.
“This pattern suggests high convergence in domains governed by explicit methodological criteria and greater divergence in domains requiring more nuanced interpretation.”
Quote in the paperSubstantial claimMay combine two claims.
PremisereasoningPrior studies mainly focus on decision-level agreement and do not assess whether model outputs are grounded in the trial reports used as source evidence.
“However, these studies mainly focus on decision-level agreement and do not assess whether model outputs are grounded in the trial reports used as source evidence.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Study design and conductreasoningThe chunk size of 1400 characters with 200-character overlap was selected to balance sufficient local context per passage with retrieval precision, and the overlap helped ensure that claims spanning chunk boundaries were not missed.
“The chunk size was selected to balance sufficient local context per passage with retrieval precision; the 200-character overlap helped ensure that claims spanning chunk boundaries were not missed.”
Quote in the paperNot a substantial claimMay combine two claims.
Interpretationown dataBoth retrieval depth and judge model reasoning capacity are important determinants of RtV evaluation outcomes.
“The sensitivity analyses further demonstrated that both retrieval depth and judge model reasoning capacity are important determinants of RtV evaluation outcomes, and that an appropriate top-k configuration combined with a reasoning-capable judge may provide a robust design choice for this framework.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S2 (checkable). May combine two claims.
InterpretationreasoningRetrieval-based evidence verification provides a reproducible and transparent approach for evaluating the reliability of AI-generated medical information, with direct relevance to digital health practice, evidence-based medicine, and medical informatics.
“Retrieval-based evidence verification provides a reproducible and transparent approach for evaluating the reliability of AI-generated medical information, with direct relevance to digital health practice, evidence-based medicine, and medical informatics.”
Quote in the paperNot a substantial claim- Rests on an assumption: The constrained judge LLM (GPT-5) verdicts accurately classify whether a generated claim is supported, contradicted, not found, or out of scope.
- Rests on an assumption: The top-k BM25 retrieved passages contain all evidence needed to verify each claim.
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Study design and conductnone givenFor a subset of unsupported verdicts, low similarity may partly reflect genuine underretrieval rather than paraphrasing alone, and these explanations cannot be fully disentangled using lexical and embedding diagnostics alone.
“We acknowledge that, for a subset of unsupported verdicts, low similarity may partly reflect genuine underretrieval rather than paraphrasing alone, and these explanations cannot be fully disentangled using lexical and embedding diagnostics alone.”
Quote in the paperNot a substantial claimMay combine two claims.
Interpretationown dataDifferences in hallucination rates were not primarily attributable to differences in retrieval strength and may instead reflect differences in reasoning and interpretation.
“The consistency of BM25 retrieval scores across models suggests that differences in hallucination rates were not primarily attributable to differences in retrieval strength and may instead reflect differences in reasoning and interpretation.”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationown dataLLMs often identify the correct direction of risk but frequently do so without sufficient evidentiary support.
“Together, these findings show that while LLMs often identify the correct direction of risk, they frequently do so without sufficient evidentiary support.”
Quote in the paperSubstantial claimClassified as probably not a substantial claim. May combine two claims.
InterpretationreasoningThis evaluation framework supports reproducible auditing, cross-model comparison, and systematic analysis of hallucination risk in AI-generated medical information for digital health systems.
“This evaluation framework supports reproducible auditing, cross-model comparison, and systematic analysis of hallucination risk in AI-generated medical information for digital health systems.”
Quote in the paperSubstantial claim
The paper relies on this without support.
The constrained judge LLM (GPT-5) verdicts accurately classify whether a generated claim is supported, contradicted, not found, or out of scope.
“Verification was performed by a constrained judge LLM (GPT-5). The judge received the trial identifier, question text, model output, explanation, and retrieved passages and returned structured JSON containing 1 of 4 verdicts: supported, contradicted, not found, or out of scope.”
The paper relies on this without support.
The top-k BM25 retrieved passages contain all evidence needed to verify each claim.
“BM25 was used to rank document chunks and return the top-k passages (default k=5).”
The paper relies on this without support.
Human RoB assessments used as the reference standard are accurate.
“Binary accuracy of AI-generated RoB judgments was high across all domains (90%-98%), whereas evidence support rates clustered at only 60%-65%.”
The paper relies on this without support.
The RtV framework's verdicts (supported, contradicted, not found, out-of-scope) validly measure evidence support and hallucination.
“To complement accuracy and agreement analyses, we evaluated evidence support and hallucination using the RtV metrics.”
The paper relies on this without support.
BM25 top-1 score reflects retrieval strength or access to relevant evidence.
“As BM25 scores reflect lexical relevance between queries and retrieved passages, these similar values suggest comparable access to potentially relevant evidence across models.”
The paper relies on this without support.
Semantic similarity between the LLM's rationale and retrieved passages is a valid grounding diagnostic.
“To complement BM25 lexical retrieval, we computed embedding-based semantic similarity between the LLM’s stated rationale and the retrieved passages as an additional grounding diagnostic (Multimedia Appendix 3).”
The paper relies on this without support.
RoB assessment is a well-characterized use case for evaluating evidence grounding.
“This study introduced an RtV framework to measure evidence support and hallucination in AI-generated medical information at the claim level, using RoB assessment as a concrete and well-characterized use case.”
Statistics recomputed
Every reported test result, recomputed from its test statistic and degrees of freedom. A result shows as not adding up only once an independent check has confirmed it.
- Consistentz = 20.14reported p < .001 · recomputed p < .001
“z=20.14, p < .001”
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Seven listed outcome categories conflict with an eighth in Table 3
MinorThe methods list seven outcome categories, but Table 3 additionally reports "Social outcomes" as a topic for every model.
“Assessments covered 7 outcome categories: diagnosis of mental disorders, quality of life, adverse events, psychological functioning and impairment, depressive symptoms, anxiety symptoms, and distress or posttraumatic stress disorder symptoms.”
“| | Social outcomes | 58.31 (6.43) | 41.39 (6.57) | 41.69 (6.43) | 26.95 (0.13) | 0.34 (0.01) |”
GPT-3.5 does not perform worse on both measures in every domain
MinorTable 1 reports higher domain 2 exact and binary accuracy for GPT-3.5 (50.97% and 93.57%) than for OpenAI o3-mini (49.70% and 93.48%).
“GPT-3.5 demonstrated lower performance on both measures across all domains.”
“| | Domain 2 | 49.70 | 93.48 | 0.95 | 0.92 | 0.95 | 0.86 | 37.22 |”
Quadratic κ does not always exceed linear κ
MinorTable 2 shows the reverse in domain 4 for all three models; for example, GPT-5 has linear κ=0.31 and quadratic κ=0.29.
“Across domains, quadratic κ values consistently exceeded linear κ values”
“| | Domain 4 | 0.31 | 0.29 | 0.51 |”
Exact accuracy range excludes reported values below 42%
MinorThe stated 42%-71% exact-accuracy range excludes Table 1 values, including GPT-3.5's 37.67% in domain 4. It also excludes GPT-5's 90.99% exact accuracy for the overall conclusion if that conclusion is included in the range.
“exact accuracy was substantially lower (42%-71%)”
“| | Domain 4 | 37.67 | 78.46 | 0.61 | 0.86 | 0.64 | 0.47 | 14.45 |”
Domain 5 gap does not exceed 30% for every model
MinorThe claim that domain 5 gaps exceeded 30% for all models conflicts with the 29.78% gap reported for OpenAI o3-mini.
“particularly domains 2 and 5, where gaps exceeded 30% for all models.”
“| | Domain 5 | 39.43 | 92.99 | 0.91 | 0.94 | 0.86 | 0.85 | 29.78 |”
Cites
The Cochrane Collaboration's tool for assessing risk of bias in randomised trials
Higgins, J. P. T., Altman, D. G., Gotzsche, P. C., Juni, P., Moher, D., Oxman, A. D., Savovic, J., Schulz, K. F., Weeks, L., Sterne, J. A. C., et al. (2011) · BMJ · doi:10.1136/bmj.d5928 · Cited by 33,817 · see citing works
RoB 2: a revised tool for assessing risk of bias in randomised trials
Sterne, J. A. C., Savović, J., Page, M. J., Elbers, R. G., Blencowe, N. S., Boutron, I., Cates, C. J., Cheng, H.-Y., Corbett, M. S., Eldridge, S. M., et al. (2019) · BMJ · doi:10.1136/bmj.l4898 · Cited by 33,583 · cited 1× · see citing works
“Although the revised RoB 2 tool introduced outcome-specific domains, signaling questions, and explicit decision rules to improve consistency [17], the process continues to require detailed evidence collection and justification, limiting scalability in digital evidence synthesis workflows.”
Large language models encode clinical knowledge
Singhal, K., Azizi, S., Tu, T., Mahdavi, S. S., Wei, J., Chung, H. W., Scales, N., Tanwani, A., Cole-Lewis, H., Pfohl, S., et al. (2023) · Nature · doi:10.1038/s41586-023-06291-2 · Cited by 4,083 · see citing works
The probabilistic relevance framework: BM25 and beyond
Robertson, S., & Zaragoza, H. (2009) · Foundations and Trends® in Information Retrieval · doi:10.1561/1500000019 · Cited by 3,374 · see citing works
Toward expert-level medical question answering with large language models
Singhal, K., Tu, T., Gottweis, J., Sayres, R., Wulczyn, E., Amin, M., Hou, L., Clark, K., Pfohl, S. R., Cole-Lewis, H., et al. (2025) · Nature Medicine · doi:10.1038/s41591-024-03423-7 · Cited by 1,734 · see citing works
A survey on multimodal large language models
Yin, S., Fu, C., Zhao, S., Li, K., Sun, X., Xu, T., & Chen, E. (2024) · National Science Review · doi:10.1093/nsr/nwae403 · Cited by 893 · see citing works
Minozzi, S., Cinquini, M., Gianola, S., Gonzalez-Lorenzo, M., & Banzi, R. (2020) · Journal of Clinical Epidemiology · doi:10.1016/j.jclinepi.2020.06.015 · Cited by 471 · see citing works
A framework to assess clinical safety and hallucination rates of LLMs for medical text summarisation
Asgari, E., Montaña-Brown, N., Dubois, M., Khalil, S., Balloch, J., Yeung, J. A., & Pimenta, D. (2025) · npj Digital Medicine · doi:10.1038/s41746-025-01670-7 · Cited by 423 · see citing works
Chelli, M., Descamps, J., Lavoué, V., Trojani, C., Azar, M., Deckert, M., Raynier, J.-L., Clowez, G., Boileau, P., & Ruetsch-Chelli, C. (2024) · Journal of Medical Internet Research · doi:10.2196/53164 · Cited by 413 · see citing works
Moulaei, K., Yadegari, A., Baharestani, M., Farzanbakhsh, S., Sabet, B., & Reza Afrash, M. (2024) · International Journal of Medical Informatics · doi:10.1016/j.ijmedinf.2024.105474 · Cited by 244 · see citing works
Omar, M., Sorin, V., Collins, J. D., Reich, D., Freeman, R., Gavin, N., Charney, A., Stump, L., Bragazzi, N. L., Nadkarni, G. N., et al. (2025) · Communications Medicine · doi:10.1038/s43856-025-01021-3 · Cited by 204 · cited 2× · see citing works
“…settings relevant to digital health practice, including fabricated or inaccurate references in systematic reviews [7,9], unsupported statements in clinical text summarization [8], and acceptance or elaboration of fabricated clinical details embedded in prompts during clinical decision support [11].”
Aljamaan, F., Temsah, M.-H., Altamimi, I., Al-Eyadhy, A., Jamal, A., Alhasan, K., Mesallam, T. A., Farahat, M., & Malki, K. H. (2024) · JMIR Medical Informatics · doi:10.2196/54345 · Cited by 166 · cited 3× · see citing works
“Prior work has found hallucinations in several relevant domains, including fabricated or inaccurate references in systematic reviews [7,9], unsupported claims in clinical text summarization [8], and adversarial exploitation of false clinical details in decision support systems [11].”
Choudhury, A., & Chaudhry, Z. (2024) · Journal of Medical Internet Research · doi:10.2196/56764 · Cited by 159 · see citing works
Scherbakov, D., Hubig, N., Jansari, V., Bakumenko, A., & Lenert, L. A. (2025) · Journal of the American Medical Informatics Association · doi:10.1093/jamia/ocaf063 · Cited by 154 · see citing works
Prompt Engineering Paradigms for Medical Applications: Scoping Review
Zaghir, J., Naguib, M., Bjelogrlic, M., Névéol, A., Tannier, X., & Lovis, C. (2024) · Journal of Medical Internet Research · doi:10.2196/60501 · Cited by 143 · see citing works
Armijo-Olivo, S., Ospina, M., da Costa, B. R., Egger, M., Saltaji, H., Fuentes, J., Ha, C., & Cummings, G. G. (2014) · PLoS ONE · doi:10.1371/journal.pone.0096920 · Cited by 124 · see citing works
Assessing the Risk of Bias in Randomized Clinical Trials With Large Language Models
Lai, H., Ge, L., Sun, M., Pan, B., Huang, J., Hou, L., Yang, Q., Liu, J., Liu, J., Ye, Z., et al. (2024) · JAMA Network Open · doi:10.1001/jamanetworkopen.2024.12687 · Cited by 103 · see citing works
Language models for data extraction and risk of bias assessment in complementary medicine
Lai, H., Liu, J., Bai, C., Liu, H., Pan, B., Luo, X., Hou, L., Zhao, W., Xia, D., Tian, J., et al. (2025) · npj Digital Medicine · doi:10.1038/s41746-025-01457-w · Cited by 59 · see citing works
Risk of bias assessments for selective reporting were inadequate in the majority of Cochrane reviews
Saric, F., Barcot, O., & Puljak, L. (2019) · Journal of Clinical Epidemiology · doi:10.1016/j.jclinepi.2019.04.007 · Cited by 48 · see citing works
Robertson, C., Ramsay, C., Gurung, T., Mowatt, G., Pickard, R., Sharma, P., & The UK Robotic Laparoscopic Prostatectomy HTA Study Group (2014) · Research Synthesis Methods · doi:10.1002/jrsm.1102 · Cited by 38 · see citing works
Comparing machine and human reviewers to evaluate the risk of bias in randomized controlled trials
Armijo‐Olivo, S., Craig, R., & Campbell, S. (2020) · Research Synthesis Methods · doi:10.1002/jrsm.1398 · Cited by 31 · see citing works
Moore, T. H., Higgins, J. P. T., & Dwan, K. M. (2023) · Cochrane Evidence Synthesis and Methods · doi:10.1002/cesm.12031 · Cited by 30 · see citing works
Purgato, M., Prina, E., Ceccarelli, C., Cadorin, C., Abdulmalik, J. O., Amaddeo, F., Arcari, L., Churchill, R., Jordans, M. J., Lund, C., et al. (2023) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd014722.pub2 · Cited by 27 · see citing works
Ting, Y.-T., Hsieh, T.-C., Wang, Y.-F., Kuo, Y.-C., Chen, Y.-J., Chan, P.-K., & Kao, C.-H. (2024) · DIGITAL HEALTH · doi:10.1177/20552076231224074 · Cited by 24 · see citing works
Rose, C. J., Bidonde, J., Ringsten, M., Glanville, J., Potrebny, T., Cooper, C., Muller, A. E., Bergsund, H. B., Meneses‐Echavez, J. F., & Berg, R. C. (2025) · Cochrane Evidence Synthesis and Methods · doi:10.1002/cesm.70048 · Cited by 8 · see citing works
Rose, C. J., Bidonde, J., Ringsten, M., Glanville, J., Berg, R. C., Cooper, C., Muller, A. E., Bergsund, H. B., Meneses-Echavez, J. F., & Potrebny, T. (2025) · BMC Medical Research Methodology · doi:10.1186/s12874-025-02631-0 · Cited by 5 · see citing works
Shafiullah (2025) · World Journal of Urology · doi:10.1007/s00345-025-05832-w · Cited by 2 · see citing works
(2025) · Publons reviews and discussion · doi:10.1002/cesm.70048/v1/review1 · Cited by 1 · see citing works
Flagged first, then by citations
Research works printed but not linked: 1
- 2026, NIH Policy Manual 3014: NIH Intramural Human Research Protection Program
Cited by
Still being checked.
- Authors
- Liang, Z., Sheffield, C., Butera, G., & Antani, S.
- Affiliations
- National Institutes of Health (US)
- Corresponding author
- Antani, Sameer
- Venue
- JMIR AI
- Publisher
- JMIR Publications Inc.
- Published
- 2026-09-16
- Volume
- 5
- Pages
- e93761
- ISSN
- 2817-1705 (ISSN-L)
- PMC
- PMC13628037
- OpenAlex
- W7213397745
- Semantic Scholar
- 5fbaba083328d7ca55e8a4eaeccd5806869f533a
- Cited by
- 0
- References
- 27
- FWCI
- 0.00
- Type
- journal article
- Language
- en
- Open access
- diamond
- doi.org
- Licence
- cc-by
- Locations
- JMIR AI (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- Funders
- U.S. Department of Health and Human Services
- National Institutes of Health
- Topics
- Health Sciences › Medicine › Health Informatics › Artificial Intelligence in Healthcare and Education
- Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
- Physical Sciences › Computer Science › Information Systems › Information Retrieval and Search Behavior
- Keywords
- hallucinations, large language models, risk of bias assessment, RoB 2, clinical trial reports, BM25 retrieval, AI-generated medical information, GPT-5, GPT-3.5, evidence appraisal, auditability, trust in AI-generated content, human-AI agreement
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-30.
Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-30.
Cited sources are checked by gpt-6-sol.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
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