APRI Score Calculator

AST (U/L): AST Upper Limit of Normal (U/L): Platelet Count (10⁹/L):

APRI: --

Formula

APRI = \((AST / ULN) ÷ Platelet Count (10⁹/L)) × 100

Explanation of Parameters

AST: Aspartate Aminotransferase level in the patient’s blood (U/L).
ULN: Upper Limit of Normal for AST in the lab performing the test (U/L).
Platelet Count: Number of platelets per 10⁹/L of blood.

Interpretation

APRI < 0.5: Unlikely significant fibrosis.
APRI 0.5 – 1.5: Possible significant fibrosis.
APRI >= 1.5: High probability of advanced fibrosis or cirrhosis.

References

Wai CT, 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.
WHO Guidelines for the Screening, Care and Treatment of Persons with Hepatitis C Infection, 2014.

Disclaimer

This calculator is provided for educational purposes only and is not a substitute for professional medical judgment. Clinical context, patient factors, and updated guidelines must always be considered.