# The Global Burden of Disease Study 2021 In a world where health conditions and conditions for health are always changing—both within and across borders—how should global health researchers, leaders, and organizations make decisions about where best to invest our limited resources? What kind of data is needed to best inform priorities and track progress? June 10, 2024 The Global Burden of Disease (GBD) study is a worldwide collaborative effort to quantify, measure, and analyze the causes and distribution of the world’s major diseases, injuries, and risk factors. The study aims to provide those working in global health with a rigorously collected and scientifically analyzed set of data to inform global health research, programs, and policy. The data are published in a series of capstone papers and are updated every few years. Together, the GBD studies form the largest-ever systematic effort to examine health trends globally over time . In the [newest iteration](https://www.healthdata.org/research-analysis/gbd), which began releasing in April 2024, the GBD study provides a new look at the incidence, prevalence, mortality, and disability-adjusted life-years (DALYs) for 371 diseases and injuries, as well as 88 risk factors, at the country and subnational levels from 1990–2021. Global Health Education and Learning Incubator faculty director [Sue J. Goldie](/people/sue-j-goldie-md-mph) and Assistant Professor [Zachary Ward](https://www.hsph.harvard.edu/prc/people/zach-ward-phd-mph/) from the Harvard T.H. Chan School of Public Health wrote an [editorial](https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00812-2/abstract) on the GBD’s policy and research implications in conjunction with the release of the new 2021 estimates. The 2021 estimates represent the first set of GBD data since the beginning of the COVID-19 pandemic. Comparing this data to previous and future trends will allow researchers to examine the short- and long-term effects of the pandemic, including the effects of Long COVID and other health outcomes resulting from the pandemic’s cascade of disruptions. The new data highlight the enormous health costs of the COVID-19 pandemic: the global life expectancy dropped 1.6 years from 2019 to 2021, and in 2021, COVID-19 was the leading cause of DALYs (population sum of years lived with disability and years of life lost due to premature death) globally. At the same time, the data also show how the world has made significant progress in reducing other communicable, maternal, neonatal, and nutritional diseases. In particular, HIV/AIDS and diarrheal diseases experienced the largest decreases in age-standardized DALYs compared to 2010 levels. The 2021 GBD study is also notable because for the first time, the study offers probabilistic forecasts of future global health trends that may help researchers and policymakers proactively design and adapt health policies and interventions. In a [viewpoint paper](https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00769-4/fulltext) outlining key findings of the 2021 data, the author highlights how forecasting the global burden of disease shows that life expectancy and healthy life expectancy are likely to continue improving through the year 2050, but global risks such as climate change, pandemics, and escalation of conflict threaten to derail global progress. The GBD studies are widely used by global health researchers and policymakers to conduct research, track health trends, prioritize initiatives, and design interventions. Though the GBD has several limitations, it is still a powerful tool that can be used for policy, research, and education alike. To learn more about the GBD, explore our resource pack on [The Global Burden of Disease](https://repository.gheli.harvard.edu/repository/collection/resource-pack-gbd-general), our resources on [GBD Regional and Subnational Analyses](https://repository.gheli.harvard.edu/repository/collection/resource-pack-gbd-general/resource/13400) and [GBD Global Analyses on Health Topics](https://repository.gheli.harvard.edu/repository/collection/resource-pack-gbd-general/resource/12878), or the selected resources below. Selected Resources - [Global Burden of Disease Resource Portal](https://www.healthdata.org/research-analysis/gbd), Institute for Health Metrics and Evaluation - [Global Burden of Disease Resource Centre](https://www.thelancet.com/gbd), The Lancet - [The Global Burden of Disease Study 2021 Special Issue](https://www.thelancet.com/journals/lancet/issue/vol403no10440/PIIS0140-6736(24)X0020-3), The Lancet 2024 - [Global Burden of Disease Study 2021 Estimates: Implications for Health Policy and Research](https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00812-2/fulltext), The Lancet 2024 - [Findings From the Global Burden of Disease Study 2021](https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00769-4/fulltext), The Lancet 2024 - [GBD Data and Tools](https://www.healthdata.org/research-analysis/gbd-data), Institute for Health Metrics and Evaluation Share on:- [ Facebook ](#) - [ Twitter ](#) - [ Linkedin ](#)