Goteborg Multifactorial Primary Prevention Trial

Background/Question:

The Goteborg Multifactorial Primary Prevention trial was designed to investigate whether health education could change the major coronary risk factors in a general population and if this change would affect coronary heart disease (CHD) incidence. Previous studies had measured the effects of modifying only one risk factor or used a population that was not representative.

Population/Methods:

The population consisted of a representative sample of men ages 47-55 years in Goteborg, Sweden. The study began with 10,004 men in the intervention group and about 10,000 men in each of two control groups. Intervention included antihypertensive treatment, dietary advice, and antismoking advice. Participants were randomly assigned to one of the three groups, and only those in the intervention group were examined initially, and at a second time between 1 and 4 years, and again at 10 years. Only 7,495 actually participated in the examinations and the interventions. Trial was of primary prevention and none of the subjects had clinical coronary disease at entry.

Results:

Serum cholesterol levels decreased over the 10 years in both main groups; the intervention group came out only 0.01 mMol-1 lower than the control group. Cigarette smoking decreased over the ten-year period in both groups. Both groups started at 50.7% smoking prevalence and ended up with 32.5% smokers in the intervention group and 35.4 % in the control group. Systolic and diastolic blood pressure also decreased in both groups and were not significantly different. Body weight showed a slight increase in both groups with the intervention group only slightly lower. The predicted CHD risk at the initial screenings was 7.33 percent. At the ten year examination the control group was at 5.36% and the intervention group was at 5.14%. No significant decrease in total mortality occurred in the control group or the intervention group. A 28-year follow-up study looked at the risk of stroke over the entire period of the study and found that age, diabetes and high blood pressure were independently associated with increased risk of stroke. An entry history of transient ischemic attacks, atrial fibrillation, chest pain, smoking and psychological stress was independently related to stroke from 0 to 15 years and from 16 to 21 years, as well as over the entire period. Family history of stroke or coronary disease was not significantly related to outcome. Elevated body mass index predicted stroke at the later part of the follow-up and low physical activity together with antihypertensive medication at the baseline predicted stroke incidence.

Conclusions/Discussion:

This study showed a decrease in three of the main risk factors for CHD in a general population. It was unable to show, however, that the interventions were the cause or whether the decrease in risk factors resulted in decreased mortality. The researchers concluded that major changes in the population as a whole must have been occurring to lead to the decrease in events for both the control and intervention groups. They also concluded that the study showed that risk factors and behavior in a population can change quickly and that investigators make very little impact on behavior. The follow-up study was able to demonstrate long-term effects of risk factor change. (FB/HB)