AST to platelet ratio index (APRI)
Simple noninvasive fibrosis and cirrhosis estimate.
Inputs
1 of 3U/L
U/L
× 10⁹/L
When to use
- Chronic hepatitis, especially where elastography is unavailable (WHO).
Pearls and pitfalls
- Above 2.0: cirrhosis likely (WHO); below 0.5: significant fibrosis unlikely.
Why use
Needs only AST and platelets.
APRI = (AST ÷ AST upper limit of normal) ÷ platelets (10⁹/L) × 100