Medical fact check

Medical Fact-Check Skill

Comprehensive critical appraisal and fact-checking for medical information, producing a structured report.

Scope. This is a pre-publication aid for writers, editors, and researchers — not clinical decision support. It evaluates how medical content is written and sourced; it does not diagnose, treat, or replace professional medical judgment.

Reference files. This skill bundles three reference files. Read them with paths relative to this skill's directory: references/checklist.md, references/evidence-levels.md, and templates/report-template.md. Depending on how the skill was installed, that directory is ~/.claude/skills/medical-fact-check/ (manual copy) or ${CLAUDE_PLUGIN_ROOT}/skills/medical-fact-check/ (installed as the Evidentia plugin).

Deterministic citation engine. When checking citations (Step 4), prefer the local evidentia engine over verifying each identifier by hand. Use the evidentia binary first; fall back to npx -y evidentia only if a local install is unavailable. Evidentia resolves DOI/PMID/arXiv/NCT identifiers against CrossRef, PubMed, OpenAlex, arXiv, and ClinicalTrials.gov, and emits the 4-tier classification plus lookupVerified and resolverOutcomes lookup traces. Use a cache path when possible so repeat checks are stable and fast. See Step 4 for how to call it.

Overview

This skill evaluates medical information across 15 criteria — evidence quality, citation accuracy, statistical interpretation, ethical considerations, and more — then generates a structured Markdown report with an overall A–F score and actionable improvement suggestions.

Supported Media Types

The skill auto-detects the content type and adjusts its evaluation accordingly:

Category	Examples	Key Focus
Research papers	Journal articles, preprints, systematic reviews	Evidence level, methodology, statistical rigor
News & articles	Health news, medical blogs, magazine articles	Accuracy of claims, source attribution, exaggeration
Social media	X (Twitter), Instagram, TikTok captions, Reddit, note	Brevity-induced omissions, clickbait, misinformation risk
Newsletters	Email newsletters, Substack, medical columns	Citation completeness, audience calibration
Patient materials	Leaflets, brochures, hospital handouts	Readability, completeness, fear-mongering
Video/audio transcripts	YouTube, podcasts, webinar transcripts	Verbal exaggeration, missing nuance, source attribution
Presentations	Conference slides, lecture materials, grand rounds	Slide oversimplification, citation on slides
Clinical guidelines	Practice guidelines, protocols, algorithms	AGREE II compliance, evidence grading, conflicts of interest
Marketing materials	Pharma ads, medical device brochures, supplement claims	Regulatory compliance, selective data presentation, COI
Health apps & digital	App descriptions, chatbot outputs, AI-generated content	Hallucination detection, accuracy of automated advice
Textbooks & education	Textbook chapters, CME/CPD materials, study guides	Currency, completeness, pedagogical accuracy
Infographics	Visual summaries, data visualizations, social cards	Data integrity, oversimplification, source attribution

The 15 Evaluation Criteria

1. Evidence level & study design
2. Citation & source accuracy (incl. AI hallucination detection)
3. Statistical interpretation
4. Causation vs. correlation
5. Bias & conflicts of interest
6. Exaggeration & overclaiming
7. Target population fit
8. Temporal validity
9. Jargon–readability balance
10. Ethical considerations
11. Logical consistency
12. Images & figures
13. Alternative explanations
14. Clinical relevance
15. Information completeness

Scoring

Each item is rated Excellent / Good / Fair / Poor. The overall score:

Score	Criteria
A	12+ Excellent, 0 Poor
B	12+ Excellent or Good, ≤1 Poor
C	12+ Fair or better, ≤2 Poor
D	3+ Poor
F	5+ Poor, or critical ethical issues

Workflow

Step 1: Acquire & Analyze

Receive the target medical content from the user. Depending on the input format:

• URL — use WebFetch to retrieve the content
• File path — use Read to load the file
• Pasted text — analyze directly
• Video/audio — if a transcript is provided, analyze it; if a URL is given, attempt to retrieve transcript via WebFetch

Identify the following:

• Content type: research paper, blog post, social media, patient leaflet, video transcript, etc.
• Target audience: general public, healthcare professionals, patients, researchers, etc.
• Main claims: what the content is asserting
• Citations present: whether evidence is referenced
• Language: the language of the content (evaluate in the original language)
• Public health risk level: LOW (educational, niche), MEDIUM (widely shared, actionable claims), HIGH (viral content, safety-critical claims, vulnerable populations)

Media-Specific Pre-Analysis

Adjust the evaluation lens based on detected media type:

Social media posts:

• Character/space constraints may justify brevity, but core accuracy must be maintained
• Check for misleading compression of complex findings
• Evaluate whether the post drives readers to reliable sources

Video/podcast transcripts:

• Verbal hedging may be lost in transcription — look for spoken qualifiers
• Hosts may editorialize beyond guest experts' actual statements
• Check if timestamps or show notes reference sources

Marketing materials:

• Apply heightened scrutiny for selective data presentation
• Check regulatory compliance (FDA, PMDA, EMA guidelines for claims)
• Identify undisclosed conflicts of interest

Clinical guidelines:

• Apply AGREE II framework for guideline quality assessment
• Check for systematic evidence review methodology
• Verify COI disclosures of guideline panel members

AI-generated content:

• Apply maximum citation verification rigor (hallucination detection)
• Check for "confident but wrong" patterns typical of LLM output
• Verify all specific numbers, dates, and named entities

Step 2: Load Evaluation Checklist

Read references/checklist.md (in this skill's directory — see the note at the top) with the Read tool to load the detailed 15-item evaluation checklist.

Step 3: Assess Evidence Levels

If the content references research studies, read references/evidence-levels.md with the Read tool and evaluate:

• Study design type (RCT, cohort, case report, etc.)
• Study quality (bias risk, sample size, etc.)
• GRADE assessment for overall quality
• Domain-specific considerations (pediatrics, oncology, etc.)

Step 4: Verify Citations

If the content cites papers or sources, verify them. Prefer the deterministic engine for existence and bibliographic checks, then use WebSearch for the semantic context check that the engine cannot do.

4a. Run the deterministic engine (existence + bibliographic accuracy)

If evidentia (or the verify_citations MCP tool) is available, run it on the content first. It resolves DOI/PMID/arXiv/NCT identifiers against CrossRef, PubMed, OpenAlex, arXiv, and ClinicalTrials.gov and returns Tiers 1, 3, and 4 with certainty - no model guesswork. Books (ISBN), guidelines, title-only citations, and other non-indexed sources are returned as Tier 2 ("verify manually"), never as fabrications:

evidentia check <file-or-url> --format json --cache "$HOME/.cache/evidentia/verification-cache.json" --mailto <your-email>

If the local binary is unavailable, fall back to the npm package:

npx -y evidentia check <file-or-url> --format json --cache "$HOME/.cache/evidentia/verification-cache.json" --mailto <your-email>

Use its output as the ground truth for citation existence. Inspect lookupVerified and resolverOutcomes when explaining why a citation was classified:

• Tier 1 (Verified) — the paper, preprint, or trial exists and metadata matches. Proceed to the context check in 4b.
• Tier 2 (Manual / content review needed) — the source may be real, but the engine cannot deterministically verify it or semantic use still needs review.
• Tier 3 (Bibliographic mismatch) — a real record exists, but the DOI/PMID/arXiv/NCT identifier or metadata is wrong. Record the discrepancy.
• Tier 4 (Hallucination) — the identifier resolves to nothing or to a different paper. Flag as a fabricated citation immediately; this is the highest-severity finding.

If the engine is not available, fall back to verifying each identifier manually with WebSearch (steps below).

4b. Semantic context check (Tier 2 — the engine cannot do this)

For every citation the engine marked Verified, still confirm it is used honestly:

1. Cross-check the abstract or full text against the cited claim
2. Evaluate context — is the citation cherry-picked or accurately represented?
3. Downgrade to Tier 2 (Content review needed) if a real paper is being misrepresented or cited out of context.

Manual fallback (if the engine is unavailable)

1. Search by DOI, PMID, or title to locate the original paper
2. DOI cross-verification — confirm the DOI resolves to the claimed paper (matching title, authors, journal)
3. Cross-check the abstract against the cited claims and evaluate context

AI Hallucination Detection (Critical)

AI-generated text (ChatGPT, Claude, Gemini, etc.) frequently contains plausible but fabricated citations. When a citation cannot be confirmed, perform these additional checks:

• Does the DOI point to a completely different paper? (Search the DOI directly and compare title/authors)
• Does the author actually exist and publish in this field?
• Do the journal name, volume, and page numbers match a real publication?

Do NOT stop at "could not verify." Actively determine whether the citation is unverifiable or provably fabricated.

Classify each citation into one of 4 tiers:

Tier	Classification	Description
1	Verified	Paper exists and content matches the citation
2	Content mismatch	Paper exists but is cited out of context
3	Bibliographic mismatch	Paper exists but DOI, author, or journal info is wrong
4	Hallucination	DOI points to an unrelated paper, or the paper does not exist

Step 5: Detailed Evaluation

Rate each of the 15 items using these dimensions:

• Current state: objective description of how the content handles this criterion
• Issues: specific problems identified (or "None")
• Suggestions: concrete, actionable improvements (if issues exist)
• Rating: Excellent / Good / Fair / Poor

Media-Specific Evaluation Adjustments

Criterion	Social Media	Marketing	Guidelines	Patient Materials
#1 Evidence level	Expect source links	Heightened scrutiny	GRADE required	Simplified OK
#2 Citations	At minimum, name sources	Full disclosure required	Systematic search required	Source available on request
#6 Exaggeration	Very common — flag aggressively	Primary concern	Should be absent	Watch for false reassurance
#7 Population fit	Often ignored — flag	Check indication scope	Must be explicit	Must match audience
#9 Readability	Platform-appropriate	Accessible to HCPs + public	HCP-level acceptable	6th-grade reading level
#10 Ethics	Check stigma/fear	Check manipulation	Check COI panel	Check dignity/autonomy
#12 Images	Memes, infographics	Selective visuals	Evidence figures	Clear illustrations

Step 6: Determine Overall Score

Aggregate the 15 item ratings into an A–F score using the criteria table in the Overview section.

Additionally, flag a Public Health Risk Assessment:

• LOW RISK: Content is broadly accurate; issues are minor or stylistic
• MEDIUM RISK: Content has meaningful inaccuracies that could mislead readers
• HIGH RISK: Content promotes harmful actions, contains fabricated evidence, or targets vulnerable populations with dangerous misinformation

Step 7: Generate Report

Read the report template from templates/report-template.md (in this skill's directory) with the Read tool and produce the structured report.

Required sections:

1. Content Overview — title, source, audience, date, media type
2. Overall Assessment — score, key issues summary, risk level, recommended actions
3. Detailed Evaluation — all 15 items with ratings, issues, and suggestions
4. Citation Verification Results — tier classification for each citation (if applicable)
5. Critical Concerns — flagged high-severity issues
6. Strengths — positive aspects worth noting
7. Suggested Corrections — before/after comparison text (if issues found)
8. References — sources used during evaluation
9. Evaluator Notes — overall commentary and caveats

Step 8: Deliver Report

Save the completed report as a Markdown file using Write:

• File name: medical-fact-check-report-YYYY-MM-DD.md in the current directory
• If a report with that name already exists, append a suffix: -2, -3, etc.
• Provide the user with:
  • The file path
  • A concise summary of findings (3–5 sentences)
  • The overall score and risk level
  • Top 3 most important issues to address

Step 9: Post-Correction Re-Verification (Optional)

If the user revises the content based on the report and requests re-evaluation:

1. Re-read the revised content
2. Check that flagged issues have been properly addressed
3. Update the recommended-actions checklist (mark resolved items)
4. Verify that corrections haven't introduced new problems (e.g., shifted reference numbers)
5. List any remaining unresolved issues
6. Save the updated report with a -rev2 (or -rev3, etc.) suffix

Media-Specific Handling

Social Media Posts

Short-form content requires particular attention to:

• Accuracy maintained despite brevity constraints
• Absence of critical caveats or disclaimers
• Clickbait titles or misleading framing
• Whether sources are linked or accessible
• Potential for viral spread of misinformation (amplification risk)

Video & Podcast Transcripts

Audio/video content often has unique issues:

• Host editorialization beyond guest expert statements
• Verbal hedging that doesn't survive transcription
• Unsubstantiated anecdotes presented as evidence
• Missing visual context in audio-only formats
• Show notes or descriptions that may overstate content

Conference Presentations & Slides

Slide decks present compressed information:

• Oversimplification of complex findings to fit slides
• Missing citations on individual slides
• Unpublished data presented without caveats
• Potential COI with industry-sponsored presentations
• Conclusions drawn from preliminary/incomplete data

Clinical Guidelines

Guidelines demand the highest methodological standards:

• AGREE II framework compliance
• Systematic literature review methodology
• GRADE evidence assessment
• Panel member COI disclosures
• Update currency and version control
• Patient/public involvement in development

Pharmaceutical & Device Marketing

Marketing materials require heightened skepticism:

• Selective presentation of favorable trial results
• Relative risk reduction without absolute figures
• Off-label use implications
• Regulatory compliance of claims
• Fair balance between efficacy and safety data
• Comparator selection bias

AI-Generated Medical Content

LLM-generated content requires the most rigorous citation checking:

• Apply hallucination detection to ALL citations
• Verify specific statistics, percentages, and dates
• Check for "confident confabulation" — authoritative tone on incorrect facts
• Flag instances where the AI fills knowledge gaps with plausible fiction
• Verify named entities (researchers, institutions, journals)

Patient-Facing Materials

Patient materials prioritize accessibility and safety:

• Reading level appropriate for target audience (aim for 6th-grade level for general public)
• No unnecessary fear-mongering or false reassurance
• Clear action items and when to seek professional help
• Respect for patient autonomy and informed decision-making
• Cultural sensitivity and inclusivity

Best Practices for Report Writing

1. Be specific — not "there is a problem" but "Section 3, paragraph 2 claims X, but the cited study actually found Y"
2. Be constructive — always pair criticism with a concrete suggestion
3. Be balanced — acknowledge strengths alongside weaknesses
4. Cite your sources — reference the guidelines or papers that inform your evaluation
5. Consider the audience — evaluation standards differ for professional vs. public content
6. Stay practical — improvement suggestions should be realistic and actionable
7. Disclose limitations — acknowledge what this AI-based review can and cannot verify

Caveats

1. Not a substitute for expert judgment — this is an AI-based evaluation tool
2. Full-text access is limited — verification relies on abstracts, open-access articles, and bibliographic metadata
3. Image evaluation is limited — cannot deeply analyze embedded figures or video content
4. Rapidly evolving fields — the most current evidence may not yet be indexed
5. Final medical decisions should always be made by qualified healthcare professionals

Reference Files

• references/checklist.md — detailed 15-item evaluation checklist
• references/evidence-levels.md — evidence hierarchy & quality assessment tools
• templates/report-template.md — structured report template

External References

• Cochrane Handbook for Systematic Reviews of Interventions
• GRADE Working Group
• AGREE II (Appraisal of Guidelines for Research & Evaluation)
• AMSTAR 2 (A MeAsurement Tool to Assess systematic Reviews)
• CONSORT, STROBE, PRISMA reporting guidelines
• FDA / PMDA / EMA advertising and promotion regulations
• DISCERN (quality of health information for patients)
• HONcode (Health On the Net Foundation)