Covid cut life expectancy by 1.6 years globally, but the leading causes of death haven’t changed since 1990

The leading causes of death haven’t changed since 1990 — with one glaring, pandemic-sized exception. 

According to the latest analysis of the Global Burden of Disease study, which reviewed  deaths from 288 causes in over 200 states and territories, Covid-19 was the only condition that broke into the ranks — if only for two years — of the global population’s traditional top five killers: ischemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2020 and 2021, Covid-19 was the second-leading cause, pushing stroke to third position. 

The study, published Thursday in The Lancet, is the most comprehensive effort to quantify health gains and losses around the world. It found that the years 2020 and 2021 undid a lot of earlier success in increasing life expectancy, which had risen by 6.2 years between 1990 and 2019,  only to fall by 1.6 years globally during the pandemic (with another 0.6 years attributed to pandemic-related causes). And while the progress continued in some pockets (for instance, in East Sub-Saharan Africa) even during the pandemic, the report also points to persisting inequities. 

The regional variations tell the story. In the Andean region of Latin America, the loss in life expectancy was close to 5 years, and in Southern Sub-Saharan Africa, it was 3.4 years. Latin America and the Caribbean, and Sub-Saharan Africa were the only two regions where Covid-19 was the leading cause of death in 2020. 

Conversely, high-income countries overall lost about a year of life expectancy attributable to Covid-19, with the high-income Asia Pacific region experiencing virtually no loss of life expectancy. The same was true for East Asia, which the analysis suggests may have been due to successful containment strategies. 

Overall, the single main factor of progress between 1990 and 2021 has been reduction in deaths from diarrhea (which added an average 1.1 year globally).  The greatest impact from this decline in deaths from diarrhea was in East Sub-Saharan Africa, where it contributed to a gain of nearly 11 years in life expectancy. East Asia, which with 8.3 years had the second-largest gain in life expectancy, saw dramatic reduction in chronic obstructive pulmonary disease, which contributed an overall 0.9 to global life expectancy. 

Each of the regions studied by the report “showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic,” write the GBD 2021 Causes of Death Collaborators, who comprise hundreds of researchers led by Mohsen Naghavi and  Kanyin Liane Ong of the Institute for Health Metrics and Evaluation at the University of Washington. Yet the findings also show persistent inequalities, noted Debra Furr-Holden, a professor of epidemiology and the dean of New York University’s School of Global Public Health.

“During Covid, we took our eye off the ball on other diseases… we lost some progress on HIV, on malaria — the impact of that is always felt the strongest in the lower-resourced parts of the world,” she said. “With all our innovations in health and health care and vaccines and all of these mitigation strategies, we’re just not doing the work on a global scale equitably. And I think this data shows that.” 

For instance, she noted that during the pandemic there was life expectancy loss from malaria, with 90% of global cases concentrated in a region of Africa where only 12% of the world’s population lives, according to the report. 

This, she said, shows a global failure to put resources where they are needed. “Think about the monkeypox outbreak that we just had. The U.S. and Canada have thrown away millions of doses of vaccines that could have prevented M-pox. They just let it literally expire on the shelf, when we have parts of sub-Saharan Africa where the death rate from monkeypox is the same as the death rate from Covid in the U.S.,” said  Furr-Holden. 

A similar trend is highlighted by another data point. In 1990, 44 of the main causes of death were highly concentrated in geographic areas with less than half the global population. In 2021, this was the case for 58 causes of death — a pattern showing that interventions that are helping improve health conditions globally aren’t necessarily reaching all of the world equitably. 

While the report “does highlight disparities, it also illustrates great success over time for a lot of these diseases,” said Eve Wool, a senior research manager at the Institute for Health Metrics and Evaluation and a senior author of the paper. “We hope that the paper can be used like a roadmap for people to be able to look at places that have successful disease mitigation programs, like these drastic reductions in enteric infections, and be able to learn from those lessons for the places that are still experiencing those disparities,” she said.