APRI (AST to Platelet Ratio Index)
AST-to-platelet ratio index (Wai 2003) = (AST/AST-ULN)*100/platelets.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- AST
- 60 U/L
- AST upper limit of normal
- 40 U/L
- Platelets
- 150 x10^9/L
Result: APRI 1.00 - indeterminate for significant fibrosis (0.5-1.5); at or below the Wai 2003 rule-out threshold for cirrhosis (1.0).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- <=0.5
- At or below the Wai 2003 rule-out threshold for significant fibrosis.
- 0.5-1.5
- Indeterminate for significant fibrosis.
- >1.5
- Above the rule-in threshold for significant fibrosis.
- <=1.0
- At or below the rule-out threshold for cirrhosis.
- 1.0-2.0
- Indeterminate for cirrhosis.
- >2.0
- Above the rule-in threshold for cirrhosis.
What you enter
- AST
- AST upper limit of normal
- Platelets
How this is calculated
Citation
Wai 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(2):518-526. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.