AST-to-Platelet Ratio Index (APRI Score)

The APRI score was developed to provide a cost-effective alternative to liver biopsy for staging fibrosis in patients with chronic Hepatitis C. It is particularly useful in resource-limited settings where specialized tests like FibroScan or the ELF score are unavailable.

A high APRI score is strongly associated with advanced fibrosis and cirrhosis. Identifying these patients is critical for deciding on treatment urgency and initiating HCC surveillance.

Like FIB-4, the primary utility of APRI is its high Negative Predictive Value (NPV), which allows clinicians to "rule out" significant fibrosis in patients with low scores.