Revealing Sex Disparities in the Burden of Diarrheal Diseases Among Children Under 5: Global and Asian Trends and Projections, 1990-2050 - A Population-Based Observational Analysis Using GBD 2021 Data.

Background: Although the global burden of diarrheal diseases (DDs) among children under 5 years of age has declined substantially over recent decades, sex-specific disparities and regional heterogeneity across Asia-particularly regarding non-fatal outcomes-remain insufficiently characterized. This study investigated long-term global and Asian trends in the burden of DDs by sex and projected future patterns to inform equitable child health strategies. Methods: Sex-disaggregated data on incidence, prevalence, mortality, and disability-adjusted life years (DALYs) among children under 5 years of age were obtained from the Global Burden of Disease 2021 Study. Temporal trends were evaluated using estimated annual percentage changes. For Asian countries, three-level hierarchical linear mixed-effects models were used to identify factors associated with disease burden. In addition, autoregressive integrated moving average models were applied to forecast sex-specific trends over the next 30 years. Results: Between 1990 and 2021, the burden of DDs declined substantially among both males and females across all outcome measures, although males consistently experienced higher DALYs and mortality. Across Asia, considerable regional heterogeneity was observed. The largest declines occurred in Southeast Asia and South Asia, whereas the smallest declines were observed in High-income Asia Pacific. Incidence and prevalence rates decreased in most regions but plateaued or increased slightly in East Asia and High-income Asia Pacific. Multilevel analyses demonstrated significantly higher DALYs and mortality among males and revealed strong inverse associations between the Sociodemographic Index and the burden of DDs. Projections to 2050 indicate continued declines globally and across most Asian subregions; however, the greatest absolute burden is expected to remain in South and Southeast Asia, with relatively limited progress projected for Central Asia and High-income Asia Pacific. Conclusions: Despite substantial progress in reducing the burden of DDs among children under 5 years of age, marked sex disparities and regional inequalities persist across Asia. Targeted, sex-specific interventions-particularly in South Asia and Southeast Asia-remain essential to accelerate progress and promote equitable child health outcomes.