The severity of abnormality of liver blood tests does not always correlate with the severity of underlying liver blood tests, and therefore a Fibrosis Risk Assessment is used to quantify the risk of fibrosis.

There are a number of FRA tools that can be used, including:

• NAFLD (specific to fatty liver disease only)
• Fib-4
• AST:ALT ratio (ratio greater than 1 identifying a high risk of liver fibrosis)

For the purposes of the All-Wales Liver Blood Tests pathway, an automatic AST:ALT ratio is being adopted as a reflex FRA when a patient is sent for an additional liver blood test.

If a patient has a score that categorises them as high risk of liver fibrosis, this does not confirm the diagnosis of liver fibrosis and the patient should be referred to a Hepatology Outpatient clinic for additional testing.