In the preceding articles a preventive screening model in two factories was described, the results were given and the exactitude of laboratory tests presented. In this paper the relations are studied between all the observed variables. Contingency-tables and the x2-statistic are used. For the 57 observed variables-(laboratory variables, e.g. triglicerides, cholesterol, glucose, uric acid, creatinine and questionnaire-items designed to screen for angina pectoris, myocardial infarction, claudicatio intermittens and bronchitis)-all possible contingency tables between two variables were calculated (1596 tables). The significant connections are reported in form of a hypothesis-matrix. There exists no statistical correlation between laboratory tests and questionnaire-items. The anamnestic questionnaire cannot be replaced by laboratory tests and vice versa. Nearly all items of the questionnaire are correlated. There are some correlations between laboratory tests, blood pressure and smoking habits.