Classical Statistical Method Research Articles

Selection and Assessment of Laboratory Tests for the Evaluation of Liver Functional Impairment

SummaryA large number of biochemical tests is at present available for the evaluation of the different aspects of the liver function. As a consequence, the requirement of laboratory investigations is generally increasing in clinical practice. However, the usefulness of such a tendency in liver investigation is questionable: the doubt concerns both the diagnostic efficacy of new individual tests and the opportunity of a progressive increase in tests requirement.This paper deals with the problem of selecting liver tests on the basis of their information content with respect to different aspects of liver function. The study was performed on 288 normal and pathological subjects. Two different methods were used: a classical statistical feature selection method, and a method based on the probability theory developed in the framework of the fuzzy sets theory. The ranking of the tests was based on the estimated misclassification rate.The results obtained appear quite relevant from a practical point of view: no effective improvement in liver functional assessment is reached by using more than 3 or 4 selected tests among the many available for each of the functional aspects considered.A reasonable compromise between diagnostic efficacy, feasibility, and costs indicates that the following groups of tests could be proposed for the functional assessment of liver diseases in clinical routine: Albumin, Pseudo-cholinesterase, and Prothrombin Time for biosynthesis and metabolism; Bilirubin, Gamma-glutamyl-transpeptidase, Bile Acids (fasting) for cholestasis; Aspartate Aminotransferase, Alanine Aminotransferase, Isocitrate-dehydrogenase, for cytolysis; Gamma-globulin, G, A and M Immunoglobulin for reactivity.