In the medical field, evidence-based medicine (EBM) is attracting attention as a means of avoiding variations in diagnosis and treatment due to doctors' differ ing experience and knowledge. EBM provides a course of action in which the best available scientific evidence is first understood and then medical treat ment is given to individual patients in consideration of their specific clinical sit uations and value systems. The practice of EBM entails integration of a doctor's individual clinical expertise with clinical evidence obtainable from systematic studies, clinical epidemiological studies, and other studies performed at exter nal institutes. EBM provides a method of prior and posterior evaluation to avoid the common tendency of clinical diagnosis and treatment to vary depend ing on the experience and knowledge of individual doctors . A doctor faced with a large number of scientific opinions, clinical test results, and so on must make decisions by a pattern recognition process. The Mahalanobis-Taguchi (MT) method is helpful in EBM because it provides a common standard, not influ enced by doctors' experience and knowledge, that can be applied to this type of pattern recognition. In the present experiment, a unit space was formed from thirty (30) persons in normal health, and D2 was calculated from patient data. Disease progress and effects of treatment were evaluated from trends in both the D2 values and clinical test results. Worsening or improvement of a patient's condition could be determined from an increase or decrease in the value of D2. The single numerical D2 value is all that is needed to arrive at a common diag nosis independent of the doctor's knowledge and experience.
