Health inequalities in disease burden of dementia and early-onset dementia: findings from the Global Burden of Disease 2021 study

Abstract

Background: Given the increasing aging global population and advancements in dementia action plans, the latest disparities in the dementia burden may evolve. This study aimed to analyze and compare temporal trends at regional, national, and sociodemographic levels to provide evidence for public health planning and resource prioritization.

Methods: The age-standardized prevalence rate (ASPR), age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR), and age-standardized disability-adjusted life years (DALYs) rate (ASDR) were derived from the Global Burden of Disease 2021 study. Estimated annual percentage changes (EAPCs) were calculated to quantify their temporal trends. Correlations between EAPC and the human resources for health (HRH) were assessed using Pearson correlation analysis.

Results: Although the ASPR and ASIR remained stable or decreased globally, they both greatly increased in East Asia (ASPR: EAPC = 0.43; 95% CI 0.35, 0.51; ASIR: EAPC = 0.40; 95% CI 0.33, 0.47). For early-onset dementia, the ASPR (range of EAPC = 0.03-0.17) and ASIR (range of EAPC = 0.05-0.19) in the 45 to 59 years age group increased in North Africa and Middle East, particularly among females (ASPR: range of EAPC = 0.08-0.21; ASIR: range of EAPC = 0.09-0.2). Although the ASMR and ASDR both decreased globally and in high socio-demographic index region, they both increased greatly in South Asia (ASMR: EAPC = 0.7; 95% CI 0.66, 0.75; ASDR: EAPC = 0.40; 95% CI 0.37, 0.43). For early-onset dementia, the ASMR (range of EAPC = 0.43-0.78) and ASDR (range of EAPC = 0.19-0.33) in the 40 to 59 years age group had increased in Central Sub-Saharan Africa, particularly among females (ASMR: range of EAPC = 0.5-0.86; ASDR: range of EAPC = 0.19-0.4). Negative correlations were observed between the EAPC in ASPR, ASIR, ASMR and ASDR with various types of HRH at the national level.

Conclusions: Although there has been progresses in controlling the global trends of dementia incidence, prevalence, and mortality, significant regional and national inequalities remain evident. More importantly, the early-onset dementia burden is increasing significantly among females in the African region, underscoring the critical need for healthcare systems that address dementia across the early midlife span.

Keywords: Dementia; Early-onset; Health disparities; Incidence; Mortality.

Fig. 1

Global dementia burden by gender and age groups in 2021

Fig. 2

The global and regional EAPC of age-standardized prevalence rate and age-standardized incidence rate by the gender and age group. Notes: EAPC estimated annual percentage change

Fig. 3

The correlations between EAPC of age-standardized incidence rate and HRH. Notes: EAPC estimated annual percentage change; HRH human resources for health

Fig. 4

The global and regional EAPC of age-standardized mortality rate and age-standardized DALYs rate by the gender and age group. Notes: DALYs disability adjusted life years; EAPC estimated annual percentage change

Fig. 5

The correlations between EAPC of age-standardized mortality rate, age-standardized DALYs rate, and, SDI and HAQ index. Notes: DALYs disability adjusted life years; EAPC estimated annual percentage change; HAQ healthcare access and 1uality index; SDI socio-demographic Index