AST:platelet ratio index
From IDWiki
[math]\displaystyle{ APRI = \frac{AST \div ULN_{AST}}{\text{platelets} \times 10^9} \times 100 }[/math]
[math]\displaystyle{ APRI = \frac{AST \div ULN_{AST}}{\text{platelets} \times 10^9} \times 100 }[/math]