Seven Countries Study. First 20-Year Mortality Data in 12 Cohorts of Six Countries

Abstract

Out of the original 16 cohorts in the Seven Countries Study on Cardiovascular Diseases, 12 population samples in six countries have reached the 20 year follow-up deadline. Data on mortality became fully available for a total of 8287 men aged 40-59 at entry examination (two cohorts in Finland, one in the Netherlands, three in Italy, two in Yugoslavia, two in Greece, and two in Japan).

Death rates from CHD as well as from all causes follow the traditional falling north to south trend (18 fold between the extremes for CHD; 2.7 fold for total mortality). The differences in all causes mortality are, however, largely accounted for by the variation in CHD mortality. The mean entry levels of serum cholesterol and representative levels of the consumption of saturated fats, mono-unsaturated fats, poly-unsaturated fats and carbohydrates explain a large proportion of inter-cohort difference in CHD mortality (81% for saturated fats).

By applying the proportional hazards model to the pools of national cohorts, with CHD deaths as end-point and five risk factors as covariates, only age and mean blood pressure are universally significant predictors of fatal events. Cholesterol, smoking habits, body mass index and physical activity play some part but not in all the pools.

Age and mean blood pressure are also the only universal risk factors for all causes of death.

Key Words:

• coronary heart disease
• epidemiology
• risk factors
• total mortality
• prediction.