Down syndrome burden in China and globally: a comparative analysis of 1990-2021 trends and future projections based on GBD 2021 database

Abstract

Background: Down syndrome (DS), a neurodevelopmental disorder caused by a chromosomal abnormality, poses a major burden on global health. Analyzing the disease burden of DS, both in China and globally, is crucial for refining public health strategies.

Methods: Using the Global Burden of Disease (GBD) 2021 database, we examined age-standardized incidence rate (ASIR), age-standardized prevalence rate (ASPR), age-standardized mortality rate (ASMR), and age-standardized disability-adjusted life year rate (ASDR) for DS in China and globally from 1990 to 2021. Joinpoint regression analysis was applied to identify temporal trends by calculating the annual percent change (APC) and average annual percent change (AAPC). A bayesian age-period-cohort (BAPC) model was further employed to project prevalence changes from 2022 to 2036.

Results: From 1990 to 2021, China's ASIR decreased from 1.68 per 100,000 to 1.18 per 100,000, compared to a global reduction from 1.27 per 100,000 to 0.97 per 100,000. Similarly, ASPR in China fell from 28.01 per 100,000 to 24.8 per 100,000, while globally it dropped from 27.98 per 100,000 to 21.07 per 100,000. Notably, China experienced steeper declines in ASMR (EAPC = -4.18%) and ASDR (EAPC = -3.87%) compared to the global averages (-0.44% and -0.69%, respectively). Joinpoint regression analysis shows that from 1990 to 2021, China's ASIR (AAPC = -1.15, p < 0.001), ASPR (AAPC = -0.39, p < 0.001), ASDR (AAPC = -2.87, p < 0.001), and ASMR (AAPC = -3.08, p < 0.001) for DS all decreased. The SDI was negatively correlated with ASMR (R = -0.68, p < 0.001) and ASDR (R = -0.66, p < 0.001) but positively associated with ASIR (R = 0.55, p < 0.001) and ASPR (R = 0.80, p < 0.001). Projections from the BAPC model suggest that the ASPR of DS will continue to decline both in China and globally through 2036.

Conclusion: From 1990 to 2021, the disease burden of DS declined in China and globally. China's decline in ASMR and ASDR outpaced the global level, though ASIR and ASPR remained higher. To further reduce DS burden, future efforts should prioritize early identification, counseling for informed decision-making, and equitable access to quality lifelong multidisciplinary support for affected individuals.

Keywords: Down syndrome; bayesian age-period-cohort model; global disease burden; joinpoint regression; socio-demographic index.

Figure 1

Joinpoint analysis of disease burden of DS in China and globally, 1990–2021: (a) ASIR, (b) ASPR, (c) ASDR, and (d) ASMR. APC: annual percentage change; ASIR: age-standardized incidence rate; ASPR: age-standardized prevalence rate; ASMR: age-standardized death rate; ASDR: age-standardizeddisability-adjusted life year rate; DALYs: disability-adjusted life years.

Figure 2

Trends in age-standardized rates of disease burden indicators for China, globally, and across different SDI regions from 1990 to 2021. (a) Trends in ASIR; (b) Trends in ASPR; (c) Trends in ASDR; (d) Trends in ASMR. ASIR: age-standardized incidence rate, ASPR: age-standardized prevalence rate, ASMR: age-standardized death rate, ASDR: age-standardized disability-adjusted life year rate, DALYs: disability-adjusted life years, SDI: social-demographic index.

Figure 3

Association between ASIR (a), ASPR (b), ASDR (c), and ASMR (d) of DS and SDI in 21 regions from 1990 to 2021. ASIR: age-standardized incidence rate, ASPR: age-standardized prevalence rate, ASMR: age-standardized death rate, ASDR: age-standardized disability-adjusted life year rate, DALYs: disability-adjusted life years, SDI: social-demographic index.

Figure 4

Trends and projections of ASPR for full sex (a), male (b), and female (c) in China and for full sex (d), male (e), and female (f) in the global DS from 1990 to 2035. Solid points and solid lines indicate the observed values, and the vertical dashed line indicates the position at which the prediction starts. Blue shading indicates the 95% highest density interval of the predicted value, as predicted by the BAPC analysis. ASPR: age-standardized prevalence rate.