Global Life Expectancy Increased

Despite the challenges of the COVID-19 pandemic, the super region of Southeast Asia, East Asia, and Oceania experienced the largest net gain in life expectancy of 8.3 years between 1990 and 2021 which was largely driven by reductions in mortality from stroke, chronic respiratory disease, cancer, and lower respiratory infections. South Asia had the second largest net gain in life expectancy of 7.8 years among the super regions, primarily driven by steep declines in deaths from diarrheal diseases. 

"Our study presents a nuanced picture of the world's health," said Dr. Liane Ong, co-first author of the study and a Lead Research Scientist at the Institute for Health Metrics and Evaluation (IHME). "On one hand, we see countries' monumental achievements in preventing deaths from diarrhea and stroke," she said. "At the same time, we see how much the COVID-19 pandemic has set us back."

The updated estimates documented an enormous loss of life during the pandemic along with pinpointing the reasons behind the improvements in life expectancy in every super region. Across the different causes of death, there were sharp decreases in death from enteric disease which is a class of diseases that includes typhoid and diarrhea, and these improvements increased global life expectancy by 1.1 years between 1990 and 2021, paired with reductions in death from lower respiratory infections adding 0.9 years. Progress in preventing deaths from other causes such as stroke, neonatal disorders, cancer, and ischemic heart disease also drove up global life expectancy, the reduction in deaths from each disease was most pronounced between 1990 and 2019.

On a regional level, Eastern sub-Saharan Africa experienced the largest increase in life expectancy of 10.7 years between 1990 and 2021 which was largely driven by improved control of diarrheal diseases. East Asia had the second largest gain driven by the region’s successful efforts of preventing deaths from chronic obstructive pulmonary disease. 

The updated estimates also highlight areas that have made huge strides in preventing deaths from major diseases and injuries, emphasizing how some of the most burdensome diseases have become concentrated in certain locations and suggests opportunities for intervention. For example, deaths from enteric diseases appeared to be concentrated in sub-Saharan Africa and South Asia during 2021; and in a stretch of land running from Western sub-Saharan Africa through Central Africa to Mozambique which represents 12% of the global population, 90% of deaths from malaria occurred in this area. 

"We already know how to save children from dying from enteric infections including diarrheal diseases, and progress in fighting this disease has been tremendous," said Professor Mohsen Naghavi, the study's co-first author and the Director of Subnational Burden of Disease Estimation at IHME. "Now, we need to focus on preventing and treating these diseases, strengthening and expanding immunization programs, and developing brand-new vaccines against E. coli, norovirus, and Shigella," he added.

Additionally, the updated estimates revealed growing threats from non-communicable diseases like kidney disease and diabetes which are increasing at alarming rates in every country. The research points to uneven progress against certain conditions such as cancer, stroke, and ischemic heart disease. While high-income countries appear to be driving down death from many types of non-communicable diseases, many low-income countries have not.

"The global community must ensure that the lifesaving tools that have cut deaths from ischemic heart disease, stroke, and other non-communicable diseases in most high-income countries are available to people in all countries, even where resources are limited," said Eve Wool, senior author of the study and a Senior Research Manager at IHME.