Program for maintaining Bayesian frames

A program, called Aerostat, that automates the process of generating the disease symptom probabilities necessary for the Bayesian-based Help (Health Evaluation through Logical Processing) medical expert system is described in this document. This program takes as input a probabilistic frame (logic module) and a HELP patient data file, and return the probabilities necessary for the frame based on the frequency with which the relevant data occurred in the file. This computer software was tested by generating the probabilities for four Help diagnostic frames (bacterial pneumonia, spontaneous pneumothorax, adult respiratory distress syndrome, and congestive heart failure) based on one of two different data files (one containing 526 patients; the other containing 3960 patients). The results from Aerostat were compared to those obtained by STRATOII, a research tool that can be used to perform a database search by manually entering all the disease/symptom codes. In all possible comparisons the results were identical, but Aerostat produced the query program automatically. The project is presently in operation at LDS Hospital as a protype system of maintenance of statistical information in diagnostic modules.