Qualitative and quantitative evaluation of liver diseases: Functional classifications

Abstract

The problem of the best use of experimental data for qualitative and quantitative evaluation of liver disfunction is analysed. Only statistical procedures for classification are considered. Emphasis is placed on a complete description of the most important steps that must be performed (degree of clustering of the data, validity of the hypotheses underlying the statistical methods used, meaning and adequate use of the reference classification, reliability of the different statistical methods used, information content of the laboratory tests studied) since the omission of any of them may contribute to a misleading interpretation of the overall results or may prevent significant practical utilization. An application to BSP tests is carried out: results obtained from 350 subjects are presented and discussed. A classification related to the main functional aspects of liver impairment was chosen. Different combinations of the parameters obtained from BSP blood disappearance curve — initial disappearance rate (K 1), 45 min-retention of total (RT45) and conjugated (RC45) BSP- and different mathematical algorithms are compared. Five classes (N, normal subjects; PN, paranormal subjects; H, prevalent hepatocellular damage; C, prevalent cholestatic damage; HC, heavy combined damages) can be satisfactorily discriminated with all three parameters (K 1 + RT45 + RC45); however K 1 + RC45 give almost the same results and represent an interesting compromise between data information content and laboratory complexity.