# Blood Test Explainer Tools — Safety Testing Record **Document Version:** 2.0 **Date:** 28 December 2025 **Clinical Lead:** Dr Yadavakrishnan Pasupathi (MBBS MBA MRCGP) **Tools Covered:** Claudius (Learning Tool), Aryash Blood Test Explainer (Results Guide) **Live URL:** https://aryash-tools.vercel.app --- ## 1. Pre-Release Testing Summary ### Issues Identified During Clinical Review | Issue | Tool | Severity | Resolution | |-------|------|----------|------------| | Fasting glucose 6.0 mmol/L shown as "normal" | Claudius | High | Changed boundary: normal now 3.5–5.9, pre-diabetic 6.0–6.9 | | Potassium upper limit 5.0 causing undue anxiety | Both | Medium | Extended to 5.3 mmol/L (within UK lab variation) | | PSA test displayed without limitation warning | Claudius | High | Added prominent warning box about PSA limitations | | Sex-specific ranges not displayed | Claudius | Low | Accepted for learning tool; Aryash shows full ranges | | Lab variation not clearly communicated | Both | Medium | Added prominent disclaimers to always check own report | | "Ferritin 15" example implied interpretation | Hub | Medium | Changed to "My ferritin is marked 'low' — what should I ask my GP?" | | No Privacy/Terms pages | Site | Medium | Created dedicated privacy.html and terms.html pages | | "Unlimited" wording confusing | Hub | Low | Changed to "Any test" in comparison table | ### Fixes Applied — 28 December 2025 **Phase 1: Clinical Corrections** 1. **Fasting Glucose Boundary Correction** - Before: 6.0 = normal, 6.1 = high - After: 5.9 = normal, 6.0–6.9 = pre-diabetic (borderline), 7.0+ = high - Aligns with NHS/NICE guidance 2. **Potassium Range Adjustment** - Before: 3.5–5.0 mmol/L - After: 3.5–5.3 mmol/L - Reduces false anxiety; within UK laboratory variation 3. **PSA Warning Added** - Added warning: "A raised PSA does not necessarily mean cancer... a normal PSA does not completely rule out prostate cancer" - Displayed prominently when PSA test selected 4. **Lab Variation Disclaimers** - Added to both tools: "Always compare your result to the reference range printed on your actual test report" **Phase 2: Legal/Compliance** 5. **Interpretation Boundary Fixed** - Changed marketing example from specific value interpretation to question-focused - Now reads: "My ferritin is marked 'low' — what should I ask my GP?" 6. **Privacy Page Created** (privacy.html) - Documents zero data collection policy - Explains local browser processing - Notes Vercel hosting infrastructure 7. **Terms of Use Page Created** (terms.html) - Educational purpose disclaimer - Limitation of liability - Reference range variation warning **Phase 3: Patient Experience Improvements** 8. **Category Filter Buttons** — Results Guide now has quick-filter buttons (Diabetes, Kidney, Liver, etc.) 9. **Tests List Preview** — Landing page shows all 35 tests covered 10. **Mobile/Accessibility Statement** — Added statement about device compatibility and offline capability 11. **Clean URLs** — Created /learn.html and /results.html for cleaner, more trustworthy URLs 12. **"Questions for GP" Teaser** — Added prominent section on hub highlighting this key differentiator **Phase 4: Patient Safety Enhancements** 13. **PWA Manifest Added** - Patients can "Add to Home Screen" on mobile devices - One-tap access when anxious about results - Works offline for poor signal areas (GP waiting rooms) 14. **"Why Do Reference Ranges Vary?" Section** - Expandable education section under each test's normal range - Explains lab variation, age/sex differences, equipment differences - Emphasises "always check YOUR report" - **Critical safety feature** — prevents misinterpretation 15. **Print GP Questions Feature** - Patients can print questions to bring to appointments - Includes checkboxes and notes section - Empowers patients in consultations --- ## 2. Safety Features Built Into Tools ### Emergency Signposting - Red banner at top of every page - "Call 999" for emergencies, "NHS 111" for urgent advice - Visible at all times, cannot be dismissed ### Clinical Disclaimers - "Educational purposes only" — repeated in multiple locations - "Not medical advice" — clear and prominent - "Cannot diagnose conditions" — explicitly stated - "Always consult your GP" — encouraged throughout - Dedicated Terms of Use page reinforcing all disclaimers ### Tool Differentiation - **Claudius:** Labelled "Learning tool only" with yellow warning banner - **Aryash:** Labelled "Results Guide" with GP questions for every test ### Reference Range Safety - "Why do reference ranges vary?" expandable section on every test - Prominent reminder to compare with own lab report - Multiple disclaimers about lab variation ### Data Protection - Zero data collection — no cookies, no tracking, no analytics - All processing happens locally in browser - Works offline after initial load - No personal or health information stored - Dedicated Privacy Policy page documenting this ### Accessibility - Skip links for screen readers - Keyboard navigation support - Focus indicators visible - PWA support for home screen installation - Works on any device (phone, tablet, computer) ### Patient Empowerment - Print Questions feature for GP appointments - Questions designed to encourage dialogue, not self-diagnosis - Notes section for patients to record GP's responses --- ## 3. Reference Range Verification Key tests verified against NHS/NICE guidance: | Test | Tool Range | NHS Standard | Verified | |------|------------|--------------|----------| | HbA1c | 20–41 normal, 42–47 pre-diabetic, ≥48 diabetic | NICE NG28 | Yes | | Fasting Glucose | 4.0–5.9 normal, 6.0–6.9 pre-diabetic | NHS Diabetes | Yes | | eGFR | ≥90 normal | NICE NG203 | Yes | | TSH | 0.4–4.0 mU/L | NHS typical | Yes | | Total Cholesterol | <5.0 mmol/L | NICE CG181 | Yes | | Potassium | 3.5–5.3 mmol/L | UK lab typical | Yes | --- ## 4. External Reviews Conducted | Reviewer | Date | Verdict | Key Feedback | |----------|------|---------|--------------| | ChatGPT | 28 Dec 2025 | "Bulletproof for patients" | Fix interpretation boundary | | Perplexity | 28 Dec 2025 | "Well-executed MVP" | Add conversion elements | | Claude.ai | 28 Dec 2025 | "Production-quality" | Highlight GP questions feature | | Gemini | 28 Dec 2025 | "Polished, professional" | Add PWA support | All feedback documented in governance folder. --- ## 5. Governance Controls ### Content Authorship - Created by Dr Yadavakrishnan Pasupathi, practising GP - AI-assisted development (Claude/Anthropic) - Clinically reviewed by author - Multiple external AI reviews conducted ### Review Schedule - Content last reviewed: December 2025 - Next scheduled review: December 2026 - Displayed on tool footer ### Change Control - All changes documented in this record - Version controlled via Git - Deployed via Vercel with audit trail - Changelog maintained --- ## 6. Regulatory Considerations ### MHRA Classification - Tool provides general educational information only - Does not interpret individual patient results - Does not provide diagnosis or treatment recommendations - Intended as patient education resource, not medical device ### DPIA Status - No personal data processed - No health data collected or stored - No DPIA required for current functionality --- ## 7. Sign-Off **Testing completed by:** Dr Yadavakrishnan Pasupathi **Date:** 28 December 2025 **Version:** 2.0 **Confirmed:** - [ ] All critical clinical values verified - [ ] Safety messaging reviewed and adequate - [ ] Emergency signposting visible and functional - [ ] Disclaimers clear and prominent - [ ] No diagnostic language used - [ ] Reference range variation warnings in place - [ ] Privacy and Terms pages created - [ ] Tool suitable for patient use **Signature:** _________________________ --- *This document should be retained for clinical governance purposes and updated following any significant changes to the tools.* *Document history: v1.0 (28 Dec 2025) Initial release. v2.0 (28 Dec 2025) Added phases 2-4 fixes, external reviews, patient safety enhancements.*