Analysis of data homogeneity of the chemical compositions of stones in case of urolithiasis

The article considers the methods for researching homogeneity of the data on chemical composition of urinary stones. Multidimensionality of the data, scarce spectrum of various values of indicators, impossibility to apply simple adequate likelihood models to them, and, also, absence of experience in such type of modeling in the field of urology are the cause of the considered problems specificity. The test of significance based on distance between sets of points in Euclidean space is suggested and analyzed. It is used to analyze a composition of stones dependence on the sex of a patient. In the case of analysis of changes in the composition of stones with time (as time goes), the proposed criterion is used as an element of pairwise comparisons of data for different time intervals. That is the first time when the idea of approximation of emerging relationships between groups of data with the help of equivalence relations is used. It allows reasonably carrying out the stratification of the original data. The experiments produced statistically valid results about the features of urolithiasis depending both on the sex of the patient and the changes over time.