Health inequalities in the global reproductive-age population: GBD 2021 trends and female-male differences, 1990–2021

Socioeconomic health inequality among reproductive-age populations remains insufficiently characterized globally. Using GBD 2021 data for individuals aged 15–49 years in 204 countries and territories, we assessed disability-adjusted life year (DALY) rates and quantified absolute and relative socioeconomic inequality using the slope index of inequality (SII) and concentration index (CI), with female-male comparisons and sensitivity analyses. In 2021, the global DALY rate was 22,377.4 per 100,000 population. From 1990 to 2021, SII changed from −17,755.23 to −13,789.27 and CI from −0.15 to −0.13. CI for communicable, maternal, neonatal, and nutritional diseases improved from −0.51 to −0.38, whereas injury CI worsened from −0.06 to −0.12. Injury SII was −824.23 in females and −2,749.96 in males. Overall socioeconomic health inequality declined but remained heterogeneous across causes and between females and males, supporting cause-specific and sex-sensitive health equity strategies.