Transparency · CHAI Applied Model Card
Liver Stress
CHAI Applied Model Card (v0.1) for the Liver Stress pattern in Zenlo Labs. This document is not CHAI-certified or CHAI-endorsed.
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Summary
The Liver Stress pattern identifies elevated hepatic transaminases and gamma-glutamyl transferase in adult laboratory panels, signaling potential hepatocellular injury or cholestatic stress. Deterministic rules compare ALT, AST, and GGT against sex-aware reference upper limits from the biomarker registry; any qualifying elevation triggers the pattern. Claude Haiku 4.5 produces a narrative summarizing which liver enzymes are abnormal for physician review. Designed for licensed functional-medicine physicians, the pattern is supportive clinical decision support — it does not stage fibrosis, diagnose NAFLD/NASH, or replace imaging or biopsy. Outputs highlight laboratory signals warranting correlation with alcohol use, medications, metabolic context, and viral hepatitis workup.
Uses & Directions
Intended use
Clinical decision support for licensed physicians reviewing hepatic enzyme elevations in adult panels.
Primary users
Licensed functional-medicine physicians and similarly qualified clinicians.
How to use
Correlate flagged enzymes with alcohol intake, medications, metabolic syndrome context, and viral hepatitis serologies as clinically indicated.
Target population
Adults aged 18 and older in the United States.
Out of scope
- Direct patient use without physician oversight
- Pediatric populations
- Standalone diagnosis of liver disease
- Fibrosis staging or elastography interpretation
Warnings
Clinical risk level
Low — supportive tool; the treating physician retains full clinical judgment and responsibility.
Known limitations
- Enzyme elevations are sensitive but not specific for etiology.
- Does not incorporate imaging, Fib-4, or NAFLD-specific scores.
- AST elevations may reflect non-hepatic sources (e.g., muscle injury).
Validation note
Validation pending — a Tier A NHANES validation run has not yet been completed for this pattern. Distribution, agreement, and fairness results will be published here when available.
Trust Ingredients
AI system facts
- Deterministic pattern detector (liver_stress) plus Claude Haiku 4.5 for narrative synthesis
- Primary inputs: ALT, AST, and GGT with sex-aware reference range comparison.
- Output: Pattern flag plus narrative on hepatic enzyme abnormalities.
Security & compliance
- Anthropic Business Associate Agreement with zero-data-retention configuration
- HIPAA-aligned design; no patient data used for model training
Ongoing maintenance
Versioned, transparent, and reproducible via a public independent audit harness (see Resources).
Transparency
Self-funded development; no third-party sponsor for this pattern card.
Key Metrics
Usefulness / Efficacy
Zenlo’s detection approach was benchmarked across five models in a separate study; see the medRxiv preprint in Resources. No per-pattern efficacy metric is published for this pattern. Source: 5-model benchmark, medRxiv 10.64898/2026.02.13.26346284.
Fairness / Equity
Validation pending — a Tier A NHANES validation run has not yet been completed for this pattern. Distribution, agreement, and fairness results will be published here when available.
Safety / Reliability
- Supportive-only; not intended as a standalone diagnostic
- Physician authorization required before clinical use
- Deterministic detector is reproducible for inputs: ALT, AST, GGT
Resources
Note: The mention or sharing of any examples, products, organizations, or individuals does not indicate any endorsement by the Coalition for Health AI (CHAI). Zenlo Labs is a clinical decision support tool intended exclusively for use by licensed healthcare providers — not a substitute for professional medical judgment, and not intended for direct patient use.
Version v0.1 · Zenlo Research