Development of a time-oriented data warehouse based on a medical information event model

We designed a new medical information event model and developed a time-oriented data warehouse based on the model. Here, the medical information event in a basic data unit is handled by a medical information system. The timing of decision making and treatment for a patient in the processing of his medical information is sometimes very critical. The time-oriented data warehouse was developed, to provide a search feature on the time axis. Our medical information event model has a unique simple data structure. PC-ORDERING2000 developed by NEC, which used Oracle, had about 600 pages of tables. However, we reduced these 600 complicated data structures to one unique and simple event model. By means of shifting clinical data from the old type order entry system into the new order entry system of the medical information event model, we produced a simple and flexible system, and the easy secondary use of clinical data of patients was realized. Evaluation of our system revealed heightened data retrieval efficiency and shortened response time 1:600 at a terminal, owing to the 1:600 reduction of the number of tables as mentioned above.