Evolving epidemiology and future trajectories of hemoglobinopathies: A global systematic analysis of burden, inequality, and projections aligning with WHO elimination strategies

Background Hemoglobinopathies, particularly sickle cell disease (SCD) and thalassemia, are escalating global public health challenges. The launch of the United Nations Sustainable Development Goals (SDGs) in 2015 prioritized universal health coverage and the control of non-communicable diseases globally. This study systematically quantifies the spatiotemporal trends in the burden of hemoglobinopathies to evaluate the potential impact of global health policies, especially the SDGs, on the disease burden. Methods Data were derived from the Global Burden of Disease Study 2021, covering 204 countries and territories. We analyzed the age-standardized rates (ASRs) of incidence, prevalence, disability-adjusted life years (DALYs), and deaths across global, regional and national levels, as well as by Socio-demographic Index (SDI) strata. The 2015 launch of the SDGs was used as a demarcation point to divide data into two periods: 1990–2015 and 2016–2021. Temporal and spatial trends in the disease burden were described using Joinpoint regression, the estimated annual percentage change, and frontier analysis. Decomposition analysis quantified the effects of demographic and epidemiological factors on the trends. A Bayesian age-period-cohort model was applied to project disease burden through 2030 and 2050. Results Globally, ASRs (per 100,000 population) of incidence, prevalence, DALYs, and mortality for SCD all increased from 1990 to 2015. During 2016−2021, its incidence and prevalence continued to increase, while DALYs and mortality slightly decreased. In contrast, all ASRs of indicators for thalassemia declined steadily over the study period. Disease burden was inversely correlated with the SDI, low-SDI regions had the highest burden of SCD, while middle-SDI regions carried the greatest thalassemia burden. For both disorders, the disease burden peaked in children under five years of age, with females facing disproportionately higher risks of mortality and disability in resource-limited settings. Thalassemia declines were primarily driven by epidemiological improvements, whereas the escalation in SCD burden was driven by population growth and epidemiological shifts, with aging serving as an offsetting factor. Although ASRs for DALYs and deaths have declined since 2015, projections suggest age-standardized prevalence for both disorders will continue to rise through 2050. Conclusions Tackling hemoglobinopathies remains a major priority for global health initiatives. While the implementation of the SDGs has contributed to mitigating the global disease burden to a certain extent, significant challenges persist: the burden of SCD is predominantly concentrated in low-SDI regions, whereas the challenges posed by thalassemia are centered in middle-SDI regions. To achieve the SDG targets, therefore, it is imperative to expand newborn screening and access to essential medicines in low-SDI settings, while simultaneously reinforcing care for migrant populations and high-risk women of childbearing age.