The global, regional, and national burdens of dementia in 204 countries and territories from 1990 to 2021: A trend analysis based on the Global Burden of Disease Study 2021.

The global population is aging, and as a consequence, the prevalence of dementia is increasing rapidly. This study aims to analyze trends in the Global Burden of Disease (GBD) and health inequalities for dementia over the period 1990 to 2021. The incidence, prevalence, and disability-adjusted life year rates of dementia in the GBD 2021 database were analyzed at the global, national, and regional levels for the period 1990 to 2021 using Joinpoint 4.9.1.0 software. The trends over the period were assessed using a combination of age-standardized rates, average annual percentage changes (AAPCs), and a sociodemographic index. The analysis revealed that, from 1990 to 2021, the global AAPC in dementia incidence, prevalence, and disability-adjusted life years amounted to 0.06 (95% confidence interval [CI]: 0.05-0.09), 0.09 (95% CI: 0.08-0.10), and 0.03 (95% CI: 0.01-0.05), respectively. Conversely, the mean AAPC in age-standardized mortality rate remained stable at 0 (95% CI: -0.02 to 0.03). The age-standardized incidence rate and age-standardized prevalence rate of dementia exhibited a positive association with sociodemographic index during the study period. The 3 regions with the highest mean AAPC in age-standardized mortality rate among the 21 GBD regions were South Africa, Central Sub-Saharan Africa, and Eastern Sub-Saharan Africa. The findings of the study indicate that the burden of dementia increases with age and is projected to remain on an upward trend until 2040. The GBD has increased significantly from 1990 to 2021, and the prevention and control of dementia represents a long-term and formidable challenge.