Highlight
The Global Burden of Disease (GBD) 2023 Study provides a comprehensive evaluation of mortality across 204 countries and extensive subnational regions from 1990 to 2023. It highlights significant shifts in leading causes of death, the transient yet profound impact of COVID-19, progress in reducing several communicable diseases, and the increasing prominence of non-communicable diseases (NCDs) especially in low-income settings. Moreover, the study refines mortality metrics by incorporating mean age at death and probability of death before 70 years, furnishing nuanced insights for health policy formulation.
Background
Understanding precise cause-specific mortality trends is imperative to design effective healthcare policies and interventions tailored to diverse populations. The GBD 2023 Study aimed at providing updated, systematically modeled estimates on deaths caused by 292 distinct etiologies, offering age- and sex-specific patterns at global, national, and subnational levels. This detailed assessment enables evaluation of epidemiological transitions, highlights areas needing public health attention, and assists in resource allocation.
Study Design and Methods
The study utilized a vast data set comprising over 55,000 sources including vital registration, verbal autopsy, cancer registries, surveys, censuses, and surveillance systems. Mortality estimates for 292 causes were modeled through the Cause of Death Ensemble Model (CODEm), which integrates multiple statistical models to optimize accuracy. Death counts, age-standardized death rates, years of life lost (YLLs), probability of dying before age 70 (70q0), and mean age at death were calculated with uncertainty intervals reflecting statistical confidence derived from 250 draws per metric. Methodological advancements included enhanced correction for COVID-19 misclassification, updated COVID-19 estimation methods, and refinement of CODEm.
Key Findings
Impact of COVID-19: The emergence of COVID-19 profoundly disrupted longstanding mortality patterns, ranking as the leading cause of global age-standardized deaths in 2021. By 2023, its impact waned, placing COVID-19 as the twentieth leading cause. This dynamic shift underscores the transient but intense mortality burden imposed by the pandemic and subsequent population-level adaptations.
Leading Causes of Death and Trends: Ischemic heart disease and stroke remain the foremost causes of death globally, although their age-standardized mortality rates have shown gradual declines, indicative of improved management and prevention. Significant reductions were also observed in diarrheal diseases, tuberculosis, stomach cancer, and measles, reflecting sustained public health successes, particularly in communicable disease control and vaccination programs.
Neonatal Disorders and Vaccine-Preventable Diseases: Despite a notable decrease in age-standardized YLLs, neonatal disorders continue to rank as the leading cause of global years of life lost, except during peak COVID-19 mortality. Vaccine-preventable ailments, including diphtheria, pertussis, tetanus, and measles, have seen substantial declines in mortality and premature death burden since 1990.
Sex and Regional Variations: Mortality patterns exhibit pronounced differences by sex and geography. For instance, deaths related to conflicts and terrorism largely increased among males in specific regions, while drug use disorders have contributed to elevated premature mortality risks (70q0), particularly for males globally. Sub-Saharan Africa experienced an increase in premature mortality from several NCDs, with observed mean ages at death lower than expected, highlighting persistent health disparities.
Mean Age at Death and Probability of Premature Mortality: Globally, the mean age at death improved significantly from approximately 47 years in 1990 to 63.4 years in 2023. Females consistently exhibited higher mean ages at death than males, with the largest disparities noted in high-income regions. The 70q0 declined across all super-regions but with heterogeneity reflecting different epidemiological and health system dynamics.
Interpretation and Clinical Implications
The GBD 2023 Study elucidates the ongoing global epidemiological transition characterized by a complex interplay between communicable diseases, NCDs, and emerging health threats like COVID-19. The study’s nuanced methodologies, including calculation of observed versus expected mean age at death, enable identification of regions and causes where mortality remains prematurely high, directing focus to healthcare system strengthening and tailored interventions.
Continuing reductions in mortality from infectious diseases signal public health progress but underline the urgent need to address rising NCD mortality, notably in low-resource settings where these diseases manifest at younger ages. The transient dominance of COVID-19 mortality illustrates the vulnerability of global health to emergent pathogens and the necessity for resilient health infrastructure capable of rapid response.
Health policy planners must integrate these insights to prioritize interventions spanning preventive vaccination programs, conflict mitigation, addiction treatment, and chronic disease management. The persistent disparities by sex and geography highlight areas for equity-focused strategies and resource allocation.
Limitations and Future Directions
Despite comprehensive data inclusion, limitations inherent to global modeling include variable data quality across regions, possible misclassification especially in low-resource settings, and residual uncertainties around emerging causes such as COVID-19. Future research should enhance real-time mortality surveillance, refine cause attribution methods, and expand subnational analyses to capture intra-country variation more accurately.
Conclusion
The GBD 2023 Study offers an unparalleled synthesis of global mortality over three decades, spotlighting major shifts influenced by pandemics, improvements in communicable disease control, and the growing burden of NCDs. These findings provide critical evidence to drive global and regional health strategies aimed at reducing premature mortality, addressing health inequalities, and preparing for future public health challenges.
Funding
This study was supported by the Gates Foundation.
Reference
GBD 2023 Causes of Death Collaborators. Global burden of 292 causes of death in 204 countries and territories and 660 subnational locations, 1990-2023: a systematic analysis for the Global Burden of Disease Study 2023. Lancet. 2025 Oct 18;406(10513):1811-1872. doi: 10.1016/S0140-6736(25)01917-8. Epub 2025 Oct 12. PMID: 41092928.
