Diagnostic effectiveness of biochemical liver-function tests, as evaluated by discriminant function analysis.

I evaluated the diagnostic value of routinely ordered liver-function tests in 175 biopsy-proven cases of hepatic disease by use of stepwise discriminant analysis. The tests studied-total and "direct" bilirubin, alkaline phosphatase, lactate dehydrogenase, and aspartate aminotransferase-correctly classified 45-73% of cases, depending on the homogeneity of the diagnostic groups. Aspartate aminotransferase and alkaline phosphatase were the best discriminators. When all tests were used in the most homogeneous groups (tumors, cirrhosis, and hepatitis), there was a stepwise improvement in diagnostic accuracy from 51 to 73%.