Do changes in cardiovascular risk factors explain changes in mortality from stroke in Finland?

Abstract

Objectives: To estimate the extent to which the changes in the main cardiovascular risk factors (blood pressure, smoking, and serum cholesterol concentration) can explain the observed changes in mortality from stroke in Finland during the past 20 years. Design: Predicted changes in mortality from cerebrovascular disease mortality were calculated by a proportional hazards model from data obtained in cross sectional population surveys in 1972, 1977, 1982, 1987, and 1992. Predicted changes were compared with the observed changes in mortality statistics. Setting: North Karelia and Kuopio provinces, Finland. Subjects: 16741 men and 16389 women aged 30-59 randomly selected from the national population register, of whom 14054 men and 14546 women participated. Main outcome measures: Levels of risk factors and predicted and observed changes in mortality from cerebrovascular disease. Results: The observed changes in diastolic blood pressure, total serum cholesterol concentration, and smoking in the population from 1972 to 1992 predicted a 44% fall in mortality from stroke in men and changes in diastolic blood pressure and smoking predicted a 34% fall in women. The observed fall in mortality from stroke was 66% in men and 60% in women. Conclusions: Two thirds of the fall in mortality from stroke in men and half in women can be explained by changes in the three main cardiovascular risk factors. Key messages In this study blood pressure and smoking were independent risk factors for stroke in both sexes and serum cholesterol concentration was also a risk factor in men Mortality fell by 62% in men and 63% in women over 20 years Changes in risk factors explained 71% of the fall in men and 54% in women Continued emphasis on promoting healthier lifestyles and effective treatment for hypertension are essential to maintain the fall in deaths