The impact of modifiable risk factor reduction on future dementia burden: a microsimulation modeling study

Area of Science:

• Neuroscience
• Epidemiology
• Public Health

Background:

• An estimated 30%-50% of dementia cases are linked to modifiable risk factors.
• The population-level impact of dementia risk reduction strategies remains uncertain.
• Accurate modeling requires considering life expectancy changes and risk factor co-occurrence.

Purpose of the Study:

• To assess the impact of interventions targeting mid-life hypertension and late-life smoking on dementia and mortality.
• To model various risk factor reduction scenarios, from partial to complete elimination.
• To evaluate effects on dementia incidence, prevalence, case numbers, and life years with and without dementia.

Main Methods:

• Utilized the MISCAN-Dementia microsimulation model.
• Simulated interventions for hypertension and smoking, including complete elimination.
• Analyzed outcomes across different reduction levels and demographic groups.

Main Results:

• All modeled risk factor reductions led to decreased dementia incidence, prevalence, and case numbers.
• Significant reductions in dementia cases were observed: 1.1%-3.3% for hypertension and 1.4%-2.5% for smoking.
• While increasing dementia-free life years, reductions caused a slight increase in dementia cases among the oldest old due to prolonged life expectancy.

Conclusions:

• Dementia risk reduction strategies, particularly for smoking and hypertension, offer substantial benefits in increasing dementia-free life years.
• A modest overall reduction in dementia cases is achievable.
• It is crucial to account for concurrent changes in life expectancy when evaluating the long-term impact of these interventions.