PEPTY: a knowledge-based program for assisting medical reasoning in peptic diseases

PEPTY is a program developed with the aim of providing a diagnostic and therapeutic assistance in managing peptic diseases. Its theoretical basis is an accurate analysis of current concepts in peptic disease diagnosis and treatment. This was done by reviewing recent literature and consulting skilled gastroenterologists. The decision tree includes three sections dealing with diagnostic, therapeutic and monitoring problems. The diagnostic section starts by evaluating clinical data from patient history and physical examination; the diagnostic hypotheses given at this level are refined and eventually confirmed by further information in the following section. Here the decision tree becomes modular in that a proper therapeutic and monitoring pathway is defined for four disease classes: gastroduodenal peptic ulcer and duodenitis, gastro-oesophageal reflux, erosive gastritis, and chronic antral gastritis. In the therapeutic section a cost-benefit analysis of possible therapeutic choices is always performed, but the final decision is made by the user. Complications, side effects and treatment efficacy are also considered and the program finally suggests the appropriate maintenance treatment. Patient data display, storage and retrieval, and explanation facilities are supplied. The system can provide a 'second opinion' in the medical practice and may be a useful learning tool for medical students.