Global, Regional, and National Burden and Trends of Down Syndrome From 1990 to 2019

Abstract

Introduction: Down syndrome (DS) is the leading cause of genetically defined intellectual disability and congenital birth defects worldwide. A large population of people diagnosed with DS globally is posing an enormous socioeconomic burden. However, the global burden and trends of DS have not been reported. Methods: Based on the data from the Global Burden of Disease database in 2019, we analyzed the incidence, prevalence, disability-adjusted life years (DALYs), and death of DS from 1990 to 2019 according to sex, age, regions, and social-demographic index (SDI). Then, age-standardized rates (ASRs) and estimated annual percentage change (EAPC) of these aforementioned indexes were calculated to evaluate the temporal trend of DS. Finally, the association of SDI with DS epidemiological parameters was assessed. Results: In the past 30 years, the incident cases, age-standardized incident rate (ASIR), and age-standardized prevalent rate (ASPR) of DS first decreased slightly and subsequently increased globally. The number of prevalent cases increased steadily, while the number and age-standardized rate (ASRs) of DALYs and deaths decreased gradually from 1990 to 2019. In the meantime, disease burdens were different across various SDI regions. The prevalent cases and ASPR for both sexes were increasing in all SDI regions except for the high-middle SDI region. At the national level, Brunei Darussalam, Ireland, and Haiti were the top three countries with the highest ASIR in 2019. Georgia was in the top three with the highest increase in ASRs of four parameters, while Serbia was consistently ranked in the top three with fastest declining. Furthermore, we found that ASIR and ASPR were positively correlated with SDI, yet the age-standardized DALYs and age-standardized death rate (ASDR) were negatively correlated with SDI. Conclusion: In the past 30 years, the burden and trends of DS were heterogeneous across different regions and countries with different sociodemographic characteristics. Great improvements had been achieved in reducing DALYs and deaths globally. However, the increased number and ASRs of incident and prevalent cases in some regions, especially in low SDI regions, were contributing to numerous challenges to public health. The findings may provide valuable information to the development or implementation of more effective measures.

Keywords: GBD 2019; disability-adjusted life years; down syndrome; incidence; mortality; social demographic index.

FIGURE 1

Burden and trends of Down syndrome globally and in five SDI quintiles from 1990 to 2019. (A) Incident cases. (B) Prevalent cases. (C) Disability-adjusted life-years (DALYs). (D) Deaths. Black bars represent males, and red bars represent females. Note: DALYs, disability-adjusted life-years; SDI, social-demographic index.

FIGURE 2

Change trends of Down syndrome incident cases, prevalent cases, DALYs, and deaths from 1990 to 2019 in different age groups. (A) Change trends of incident cases. (B) Change trends of prevalent cases. (C) Change trends of DALYs. (D) Change trends of deaths. Note: DALYs, disability-adjusted life-years.

FIGURE 3

Age-standardized rate of Down syndrome in 2019 in 204 countries and territories. (A) Age-standardized incident rate (ASIR). (B)Age-standardized prevalent rate (ASPR). (C) Age-standardized DALY rates. (D) Age-standardized death rates (ASDRs).

FIGURE 4

Estimated annual percentage changes of Down syndrome in 204 countries and territories between 1990 and 2019. (A) EAPC of age-standardized incident rates (ASIRs). (B) EAPC of age-standardized prevalent rates (ASPRs). (C) EAPC of age-standardized disability-adjusted life-year (DALY) rates. (D) EAPC of age-standardized death rates (ASDRs). Note: DALYs, disability-adjusted life-years; EAPC, estimated annual percentage changes.

FIGURE 5

Association between ASRs of Down syndrome and SDI in 21 regions from 1990 to 2019. The SDI was positively correlated with the ASIR (A) and ASPR (B) in 21 regions from 1990 to 2019. The SDI was negatively correlated with the age-standardized DALY rate (C) and ASDR (D). Note: ASRs, age-standardized rates; ASIR, age-standardized incident rate; ASPR, age-standardized prevalent rate; ASDR, age-standardized death; DALYs, disability-adjusted life-years; SDI, social-demographic index.