Global life expectancy has increased by 6.2 years since 1990, largely due to reductions in deaths from leading killers such as diarrhea, lower respiratory infections, stroke, and ischemic heart disease. However, the arrival of the COVID-19 pandemic in 2020 derailed progress in many locations. This is the first study to compare deaths from COVID-19 to deaths from other causes globally. Despite the challenges presented by the pandemic, the super-region of Southeast Asia, East Asia, and Oceania saw the largest net gain in life expectancy between 1990 and 2021, largely attributed to declines in mortality from chronic respiratory diseases, stroke, lower respiratory infections, and cancer.
The study by the Institute for Health Metrics and Evaluation (IHME) found that South Asia had the second-largest net increase in life expectancy among super-regions between 1990 and 2021, primarily due to steep declines in deaths from diarrheal diseases. COVID-19 radically altered the top five causes of death for the first time in 30 years, displacing stroke as the second-leading cause of death globally. The super-regions hit hardest by the COVID-19 pandemic were Latin America and the Caribbean and sub-Saharan Africa, which lost the most years of life expectancy in 2021. The study also highlights the reasons behind improvements in life expectancy globally, showing sharp drops in deaths from enteric diseases, lower respiratory infections, stroke, neonatal disorders, ischemic heart disease, and cancer.
At the regional level, Eastern sub-Saharan Africa experienced the largest increase in life expectancy, jumping by 10.7 years between 1990 and 2021, mainly due to control of diarrheal diseases. East Asia had the second-largest gain in life expectancy, with success in reducing deaths from chronic obstructive pulmonary disease playing a key role. The Global Burden of Disease Study 2021 measures mortality by cause of death and years of life lost at various levels, linking specific causes of death to changes in life expectancy. The study shows both the diseases that have driven increases and decreases in life expectancy and how disease patterns have shifted across locations over time.
The study also sheds light on growing threats from non-communicable diseases such as diabetes and kidney diseases, which are increasing in every country. Uneven progress has been made against conditions like ischemic heart disease, stroke, and cancer, with high-income countries driving down deaths from these diseases more successfully than low-income countries. The researchers emphasize the importance of ensuring that lifesaving tools that have reduced deaths from non-communicable diseases in high-income countries are available worldwide, even in resource-limited settings. The study underscores the need for continued efforts to prevent and treat diseases, strengthen immunization programs, and develop new vaccines to improve global health outcomes.
