Evaluation of the "Mahalanobis' generalized distance" method of quality control: monitoring system of multivariate data.

The purpose of this article is to evaluate the effectiveness of a monitoring system that utilizes the multivariate data. The system monitors the data of an individual patient by comparing them with his previous data. The Mahalanobis' generalized distance is introduced to measure the difference between the present and previous data. The authors applied this method to several sets of laboratory data, and it was shown to be useful for the monitoring system of laboratory errors. As a practical application, they developed a batch program and introduced it in the daily routine of the computer system. They expect that this method will be employed as a useful monitoring system in clinical laboratories, like the limit and delta checks.