Article Impact Level: HIGH Data Quality: STRONG Summary of The Lancet Public Health, 9(7), e443–e460. https://doi.org/10.1016/S2468-2667(24)00120-8 Dr. Naaheed Mukadam et al.
Points
- The study reviews population-based cohort studies to assess trends in dementia prevalence and incidence over time, addressing conflicting results from previous research.
- The methodology involved analyzing five systematic reviews and 27 primary papers. The results revealed that dementia incidence has declined in Europe and the USA but shows varied trends in Japan and Nigeria.
- Population-attributable fractions (PAFs) for education and smoking decreased over time, while those for obesity, hypertension, and diabetes increased, indicating shifting risk factors.
- The Framingham study highlighted a decline in dementia incidence linked to reduced PAFs for education and smoking, suggesting the impact of lifestyle interventions.
- The study calls for further research in low- and middle-income countries and emphasizes the importance of population-level interventions and continued surveillance to address the growing public health challenge of dementia.
Summary
The research delves into the evolving landscape of dementia prevalence and incidence over time, drawing from a comprehensive review of population-based cohort studies. While previous research has yielded conflicting results regarding changes in dementia rates, this study aims to synthesize evidence from systematic reviews and primary papers to assess trends in dementia prevalence and incidence. By employing consistent methodologies across multiple time points and quantifying shifts in risk factors using population-attributable fractions (PAFs), the study seeks to elucidate the impact of lifestyle and demographic factors on the changing epidemiology of dementia.
The study extensively searched for systematic reviews focusing on dementia prevalence or incidence trends over time, identifying five relevant reviews and 27 primary papers for analysis. Notably, studies from Europe and the USA consistently reported a decline in dementia incidence, contrasting with findings from Japan and Nigeria showing varied trends. The analysis revealed that PAFs for factors such as education level and smoking tended to decrease over time, while those for obesity, hypertension, and diabetes showed an increasing trend. The Framingham study in the USA demonstrated a correlation between declining incidence of dementia. It reduced PAFs for education and smoking, highlighting the potential impact of lifestyle interventions on dementia rates.
The findings underscore the potential influence of lifestyle modifications, such as education policies and smoking cessation programs, in mitigating the incidence of dementia. The study advocates for further research, particularly in low- and middle-income countries where the burden of dementia is escalating, to better understand the interplay between risk factors and dementia trends. By emphasizing the importance of population-level interventions and continued surveillance of dementia epidemiology, this research paves the way for targeted strategies to address the growing public health challenge posed by dementia worldwide.
Link to the article: https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(24)00120-8/fulltext
References Mukadam, N., Wolters, F. J., Walsh, S., Wallace, L., Brayne, C., Matthews, F. E., Sacuiu, S., Skoog, I., Seshadri, S., Beiser, A., Ghosh, S., & Livingston, G. (2024). Changes in prevalence and incidence of dementia and risk factors for dementia: An analysis from cohort studies. The Lancet Public Health, 9(7), e443–e460. https://doi.org/10.1016/S2468-2667(24)00120-8
