Global incidence, prevalence, years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE) for 371 diseases and injuries in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

The Global Burden of Disease (GBD) 2021 study provides a comprehensive analysis of health loss across 371 diseases and injuries in 204 countries and territories from 1990 to 2021. This analysis uses 100,983 data sources to calculate disability-adjusted life-years (DALYs)—a metric combining years of life lost to premature death (YLLs) and years lived with disability (YLDs)—and healthy life expectancy (HALE). The study is notable for incorporating the first comprehensive estimates of the health impact of the COVID-19 pandemic, including its direct mortality, long COVID, and indirect effects on other health conditions.

After three decades of consistent improvement, global age-standardised DALY rates increased by 4.1% in 2020 and 7.2% in 2021 compared to 2019. COVID-19 emerged as the leading cause of DALYs globally in 2021. While non-communicable diseases (such as ischaemic heart disease and stroke) remain the largest contributors to the overall burden, the pandemic reversed progress in reducing DALY rates for communicable, maternal, neonatal, and nutritional (CMNN) diseases. Notably, while some conditions like HIV/AIDS and diarrhoeal diseases continued to show health gains, other areas saw concerning trends: age-standardised DALY rates for anxiety and depressive disorders increased by 16.7% and 16.4%, respectively, between 2010 and 2021. HALE at birth also saw a global decline of 2.2% between 2019 and 2021.

The findings signal a significant inflection point in global health. The reversal of progress highlights the fragility of health systems when faced with a global pandemic. The study underscores the urgent need to prioritize non-communicable disease prevention—particularly for cardiovascular and mental health conditions—while simultaneously maintaining momentum in controlling CMNN diseases. The data provides a critical benchmark for policy makers to evaluate progress toward international health targets and to identify systemic inefficiencies that must be addressed to improve pandemic preparedness and overall population health.