Abstract Background Inflammatory Bowel Disease (IBD) exhibits significant regional and population-specific epidemiological trends, yet variations across Socio-Demographic Index (SDI) levels remain underexplored. This study aims to analyze the global, regional, and national burden of IBD from 1990 to 2021 using Global Burden of Disease (GBD) 2021 data, focusing on SDI-based disparities to inform health policies and strategies. Methods Using GBD 2021 data, the study assessed IBD burden across 204 countries categorized into five SDI levels. Metrics included incidence, age-standardized incidence rate (ASIR), prevalence, age-standardized prevalence rate (ASPR), DALYs, age-standardized DALYs (ASDR), mortality and age-standardized mortality rate (ASMR). Trends were analyzed using estimated annual percentage change (EAPC) and Joinpoint regression. Pearson coefficients examined SDI-burden correlations, and frontier analysis assessed gaps between observed and optimal burden levels. Inequality was evaluated via the Slope Index of Inequality (SII) and Concentration Index (CI). Decomposition analysis explored contributions of population growth, aging, and epidemiological changes. Results From 1990 to 2021, the global ASIR rose by 0.29% annually, while ASPR, ASMR and ASDR decreased by 0.13%, 0.31% and 0.52%. In high SDI regions, all rates increased, while low SDI regions experienced rising ASIR and ASPR but declining ASMR and ASDR. High-SDI regions experienced the highest burden, with females showing higher ASPR, ASMR, ASDR compared to males. In other SDI regions, males bore a greater burden than females. Joinpoint regression showed that ASIR and ASPR rose initially before stabilizing, while ASMR and ASDR declined. High SDI regions exhibited more trend fluctuations, while low SDI regions remained stable. In low SDI regions, population growth had the most significant impact on case numbers of incidence, prevalence, mortality, and DALYs, contributing 78.2%, 83.08%, 107.97%, and 99.43%. In high SDI regions, population growth was the dominant factor for incidence and prevalence, while population aging played a more prominent role for mortality and DALYs, contributing 63.13% and 48.93%. Inequality analysis revealed significant absolute and relative SDI-associated inequalities in the IBD burden, which varied across different time periods and sex groups. Conclusion This study highlights the significant influence of socioeconomic factors on the epidemiology of IBD. Future public health strategies should prioritize reducing health disparities across socio-economic levels and between sexes. By optimizing resource allocation and implementing targeted interventions, we can enhance health outcomes and improve the quality of life for all patients. Conflict of interest: Ms. Cheng, Yutong: No conflict of interest Wang, Ziwei: No conflict of interest Peng, Yuxin: No conflict of interest Dang, Yongze: No conflict of interest Deng, Yingfan: No conflict of interest Sha, Sumei: No conflict of interest. Liu, Xin: No conflict of interest Wang, Jinhai: No conflict of interest Shi, Haitao: No conflict of interest Xie, Ning: No conflict of interest
Cheng et al. (Thu,) studied this question.