🫀 APRI (AST to Platelet Ratio Index)
Estimate hepatic fibrosis non-invasively with the AST to Platelet Ratio Index (APRI).
APRI (AST to Platelet Ratio Index)
AST (U/L)
AST upper limit of normal (U/L)
Platelets (×10⁹/L)
When to use
Triage for fibrosis/cirrhosis where elastography is unavailable.
How it works
APRI = (AST/ULN × 100) / platelets (×10⁹/L). > 1.0 suggests significant fibrosis; > 2.0 suggests cirrhosis.
Key points
- WHO uses APRI > 2 as a cirrhosis cut-off in resource-limited settings.
- Developed in hepatitis C — performance varies by aetiology.
- Confirm with imaging/elastography where possible.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.