The Process of Finding Simple Solutions to Support Diagnostic Decisions in Medical Research on the Example of Chronic Gastritis Stage Assessment

摘要

The problem with using of mathematical methods in medical research is comprehensively considered on the practical example of sample design of patients with different stages of chronic gastritis. The chronic gastritis stage determining as a method for assessing gastric cancer risk has been performed in this approach using the author's method of surrogate samples forming. The source data are biopsies obtained in accordance with the OLGA-system protocol. The development of a marker method for identifying the stage of gastritis has been chosen as a priority. It is proposed to use the intestinal epithelium transcription factor CDX-2 such as surrogate marker which is detected in tissue during immunohistochemistry. An integral scale for the semiquantitative evaluation of this marker has also been developed. Due to the small number of available samples, two methods for resampling pseudo- experimental data are proposed. The first one is based on the method of fragments, commonly used in hydrology. The second method is linked to the well-known bootstrap with mixing constraints. The data from the previous stage with less pathological findings have been used as reference models for each next stage. The available data have been described with acceptable accuracy by one-parameter Rayleigh distributions and exponential distributions.