Abstract
OBJECTIVES: Data on health inequalities in inflammatory bowel disease (IBD) among women of childbearing age (WCBA, 15-49 years) across different countries are lacking. We aimed to assess the global incidence, disability-adjusted life year (DALY) burden and cross-country inequalities of IBD in WCBA from 1990 to 2021. DESIGN: Observational study. SETTING: Data were extracted from the Global Burden of Disease Study 2021. PARTICIPANTS: Women aged 15-49 years diagnosed with IBD. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcomes were the total numbers and age-standardised rates of incidence and DALYs. Secondary outcomes included (1) temporal trends, assessed using estimated annual percentage change (EAPC); (2) periods of significant change identified through joinpoint regression analysis and (3) health inequalities by sociodemographic index (SDI), assessed using the slope index of inequality (SII) and the concentration index. RESULTS: Globally, from 1990 to 2021, the number of incident IBD cases among WCBA increased from 60 926 (95% uncertainty interval (UI) 50 342 to 74 910) to 98 975 (95% UI 80 568 to 124 089), and DALYs increased from 193 091 (95% UI 145 850 to 245 244) to 281 580 (95% UI 223 989 to 349 966). During the same period, the age-standardised incidence rate (ASIR) increased significantly (EAPC 0.22, 95% UI 0.1 to 0.34), whereas the age-standardised DALY rate (ASDR) decreased significantly (EAPC -0.28, 95% UI -0.35 to -0.21). In 2021, the highest ASIR (14.93 per 100 000, 95% UI 11.52 to 18.97) and ASDR (27.94 per 100 000, 95% UI 19.97 to 37.87) were observed in high-SDI regions. In contrast, the fastest increase in ASIR (EAPC 1.69, 95% UI 1.48 to 1.90) occurred in middle-SDI regions. High-middle-SDI regions exhibited the most pronounced decrease in ASDR (EAPC -0.8, 95% UI -0.92 to -0.67), whereas a notable upward trend in ASDR was found solely in low-SDI regions (EAPC 0.14, 95% UI 0.07 to 0.21). The SII for ASIR increased from 4.83 (95% CI 3.63 to 6.03) in 1990 to 6.26 (95% CI 4.90 to 7.63) in 2021, whereas the concentration index decreased from 0.35 (95% CI 0.25 to 0.44) to 0.24 (95% CI 0.16 to 0.33). The SII for ASDR decreased from 7.37 (95% CI 2.07 to 12.67) in 1990 to 5.97 (95% CI 1.38 to 10.56) in 2021, and the concentration index shifted from 0.13 (95% CI 0.06 to 0.2) in 1990 to -0.03 (95% CI -0.1 to 0.05) in 2021. CONCLUSIONS: In 2021, the global incidence and ASDR burden remained concentrated in high-SDI countries, with significant regional disparities. From 1990 to 2021, health inequality in DALYs gradually shifted from high-income to low-income countries.