The primary prevention study

The Primary Prevention Trial in Goteborg is a multifactorial intervention programme on coronary heart disease, stroke incidence and total mortality. The study is administered by the Section for Preventive Cardiology, Institution of Medicine, University of Gothenburg. The study started in 1970. The intervention group consisted of 10 004 men. Two control groups were of similar size. The participants were all men in Gothenburg born in 1915-1922 and 1924-1925. The first examined group was men born in 1915 and the first screening was completed 1973 with those born in 1925. A second examination started in 1974 and was completed in early spring 1977, and the final examination was performed ten years after the first one, that is between 1980 and 1983. The participants were 47-55 years of age when the study started, and accordingly 57-65 years of age at the final examination. Participation rate at the first screening examination was 75% (n=7495). The intervention group and a 2% sample of the control group 1 received an illustrated postal questionnaire dealing with family history of heart disease and stroke, the subject's own heart symptoms, known hypertension, smoking habits, physical activity during work and leisure time, and stress. Subjects of the intervention group and the 2% sample of control group 1 were invited to a screening examination at which height, weight, total serum cholesterol, blood pressure, ECG, and some interview responses were recorded. In the control groups no further action was taken. Treatment of the risk factors of elevated serum cholesterol, elevated blood pressure and smoking was given for subjects in the intervention group. The whole intervention group was invited for a second examination. The effects of the intervention on risk factors were measured in all participants of the intervention group (n=7517), and in an 11% random sample of control group 1 (n=826) four years after they entered the study. Ten years after entry new 20% random samples of the intervention group and control group 1 were invited. Of these, 1473 in the intervention group and 1404 in control group 1 participated in the investigations. Data from the intervention group are available from SND. The purpose of the study was to: 1 - to analyse the extent to which it was possible to induce changes in risk factors in a randomly selected population sample of middle-aged Swedish men by means of a population-based intervention programme which could be managed by a limited number of physicians and paramedical personnel. 2 - to measure the effect of this intervention programme on the incidence of non-fatal and fatal myocardial infarction, stroke and the total death rate in the intervention group compared with two control groups also randomly selected from the general population.