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

Area of Science:

• Cardiovascular epidemiology
• Public health research
• Preventive medicine

Background:

• Stroke mortality rates in Finland have seen significant changes over the past two decades.
• Cardiovascular risk factors, including blood pressure, smoking, and serum cholesterol, are known contributors to stroke incidence and mortality.

Purpose of the Study:

• To quantify the impact of changes in key cardiovascular risk factors on the observed decline in stroke mortality in Finland.
• To determine the proportion of stroke mortality reduction attributable to modifiable risk factors.

Main Methods:

• Utilized data from cross-sectional population surveys conducted between 1972 and 1992 in North Karelia and Kuopio provinces, Finland.
• Employed a proportional hazards model to predict changes in cerebrovascular disease mortality based on population risk factor levels.
• Compared predicted mortality changes with observed mortality statistics from national records.

Main Results:

• Observed reductions in diastolic blood pressure, total serum cholesterol, and smoking predicted a 44% decrease in stroke mortality for men and a 34% decrease for women.
• The actual observed fall in stroke mortality was 66% in men and 60% in women during the study period.
• Changes in the three main cardiovascular risk factors accounted for approximately two-thirds of the stroke mortality decline in men and half in women.

Conclusions:

• Modest but significant improvements in population-level cardiovascular risk factors have substantially contributed to the reduction in stroke mortality in Finland.
• Public health interventions targeting blood pressure, cholesterol, and smoking cessation are effective strategies for reducing cerebrovascular disease burden.
• Further reductions in stroke mortality may be achievable through continued efforts to control major cardiovascular risk factors.