Explaining clinical decisions by extracting regularity patterns

When solving clinical decision-making problems with modern graphical decision-theoretic models such as influence diagrams, we obtain decision tables with optimal decision alternatives describing the best course of action for a given patient or group of patients. For real-life clinical problems, these tables are often extremely large. This is an obstacle to understand their content. KBM2L lists are structures that minimize memory storage requirements for these tables, and, at the same time, improve their knowledge organization. The resulting improved knowledge organization can be interpreted as explanations of the decision-table content. In this paper, we explore the use of KBM2L lists in analyzing and explaining optimal treatment selection in patients with non-Hodgkin lymphoma of the stomach using an expert-designed influence diagram as an experimental vehicle. The selection of the appropriate treatment for non-Hodgkin lymphoma of the stomach is, as for many other types of cancer, difficult, mainly because of the uncertainties involved in the decision-making process. In this paper we look at an expert-designed clinical influence diagram as a representation of a body of clinical knowledge. This diagram can be analyzed and explained using KBM2L lists. It is shown that the resulting lists provide high-level explanations of optimal treatments for the disease. These explanations are useful for finding relationships between groups of variables and treatments. It is demonstrated that these lists can act as a basis for gaining a deeper understanding of the underlying clinical problem. © 2007 Elsevier B.V. All rights reserved.