Hepatology Equation Moderate evidence Clinical review pending v1.0.0

APRI (AST to Platelet Ratio Index)

Is significant fibrosis or cirrhosis likely in chronic hepatitis?

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About this tool

Simple index of AST (relative to ULN) and platelet count for liver fibrosis.

Intended use

Adults with chronic hepatitis C (and other chronic liver diseases with lower accuracy).

Outcome

Significant fibrosis / cirrhosis

Time horizon

Point in time

Derivation population

Patients with chronic hepatitis C undergoing biopsy.

Limitations

Moderate accuracy; many indeterminate results.

Clinical problems

Liver disease

Evidence

Evidence level

Moderate evidence

Externally validated, or an established physiological equation whose clinical thresholds rest on consensus; guideline support limited or mixed. Methodology

Guideline status

Recommended by WHO (2014) for fibrosis assessment in resource-limited settings.

Evidence summaries for this tool are awaiting independent clinical review. Statistics are shown only where they could be attributed to a specific publication.

References

Original publicationWai CT, Greenson JK, Fontana RJ, et al. A simple noninvasive index can predict both significant fibrosis and cirrhosis in patients with chronic hepatitis C. Hepatology 2003;38:518-526. Find on PubMed (opens in a new tab)

Version history

Version	Formula	Effective	Reviewer	Changes
v1.0.0	Wai 2003	2026-10-03	—	Initial implementation with reference test vectors.

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Clinical decision support only. Interpret results in the context of the individual patient and current guidance; HumanPulse does not replace professional medical judgment.