This index is among the best validated methods for predicting HCV progression. At extreme values (very high or very low) the APRI can avoid further invasive testing in a substantial proportion of patients. Unfortunately, findings in validation studies suggest only moderate predictive value.
We are unaware of validated management algorithms using the APRI.
The APRI is validated in HCV referral populations, thus extending it to other conditions or populations may be misleading. Upper reference values for AST vary by laboratory, which can also significantly affect results.