Studies on Clinical Prediction of Myocardial Infarction : Quantifications of Coronary Risk Factors

The results of epidemiological studies on ischemic heart diseases in recent years have called for attention to the concept of coronary risk factors, and there are several papers on relations of the grade of significance of each risk factor to coronary heart diseases. These risk factors, however, are correlated with one anorher, and some factor, in association with some other factor or factors, exerts untoward effects, making evaluation of each factor difficult. Therefore, coronary heart diseases are now studied in terms of multivariate cause-and-effect relationship. In a study on quantitative prediction of the onset of myocardial infarction in terms of combinations of risk factors, an attempt was made at estimating the grade of significance of each one of the risk factors in there correlations by means of (I) the maximum likelihood method and (II) discrimination analysis; and a few interesting findings obtained in the study on the method of predicting the onset of myocardial infarction are presented hereunder. (I) STUDY BY MAXIMUM LIKELIHOOD METHOD Materials and Method: A total of 11, 188 materials, consisting of inpatients, outpatients and the people admitted to the human dock at the author s hospital, were followed up, and 862 materials whose prognosis was known and whose data on five factors were available weer selected as the subjects. These subjects were classed to the myocardial infarction group which comprised 94 subjects (77 males and 17 females), and the control group which comprised 768 subjects (556 males and 212 females), including 53 patients of angina pectoris without the onset of myocardial infarction during the follow-up period of not less than one year. The average age of the myocardial infarction group was 60.3 years, and that of the control group 52.6 years.