Here’s why global life expectancy went up by 6.2 years

By Imogen Howse via SWNS

Global life expectancy has increased by more than six years since 1990, a new study has revealed.

Reductions in deaths from leading killers such as diarrhea, lower respiratory infections such as bronchitis and pneumonia and stroke fuelled this progress.

Improved healthcare and better disease prevention also helped people live longer, but COVID-19 sadly derailed progress in many countries and regions.

Researchers from the Institute for Health Metrics and Evaluation (IHME) studied causes of death around the world over the last three decades and analyzed how global life expectancy changed during that period.

They found that overall, life expectancy is up by 6.2 years since 1990, with the most pronounced reduction in deaths recorded between 1990 and 2019, before the pandemic hit, particularly in Oceania, east Asia, and eastern sub-Saharan Africa.

This was driven by a sharp drop in deaths from enteric diseases – including diarrhea and typhoid – and significantly reduced mortality from lower respiratory infections.

Eastern sub-Saharan Africa experienced the largest life expectancy increase of 10.7 years.

The super-region of southeast Asia, east Asia, and Oceania saw the largest net gain in life expectancy, 8.3 years, largely due to drops in deaths from stroke, lower respiratory infections, chronic respiratory diseases, and cancer.

The area’s management of the pandemic also helped preserve its life expectancy gains, the team said.

South Asia was the super-region with the second largest net gain7.8 years, which has been attributed to a steep decline in deaths from diarrhoeal diseases.

East Asia followed closely behind, with improvements attributed to the slashing of deaths from chronic obstructive pulmonary disease.

The study, published in The Lancet, also highlights how COVID-19 altered the top five causes of death for the first time in 30 years – replacing a long-dominant killer, stroke, to take second place.

Researchers found that the super-regions of Latin America, the Caribbean, and sub-Saharan Africa were hit the hardest by the pandemic – losing the most years of life expectancy in 2021.

Dr. Liane Ong, co-first author of the study and a Lead Research Scientist at IHME, in Seattle, US, said: “Our study presents a nuanced picture of the world’s health.

“On one hand, we see countries’ monumental achievements in preventing deaths from diarrhoea and stroke.

“At the same time, we see how much the COVID-19 pandemic has set us back.”

Dr. Ong added that the study can help scientists deepen their understanding of death-reduction strategies – and offer more information on what kinds of public health interventions are successful.

The study's findings also revealed which diseases have become more concentrated in certain locations, which co-first author Professor Mohsen Naghabi, the Director of Subnational Burden of Disease Estimation at IHME, said can help with prevention and treatment.

He said: “Our study shows that in 2021, deaths from enteric diseases were largely concentrated in sub-Saharan Africa and South Asia.

“Likewise, 90 percent of deaths from malaria occurred in an area inhabited by just 12 percent of the world’s population – a stretch of land ranging from western sub-Saharan Africa through central Africa to Mozambique.

“We already know how to save children from dying from enteric infections including diarrhoeal diseases.

“But now, we need to focus on preventing and treating these diseases, strengthening and expanding immunization programs, and developing brand-new vaccines against illnesses such as E. coli, norovirus, and Shigella.”

Finally, the study also revealed a growing risk of death worldwide from non-communicable diseases, including diabetes.

It also demonstrated that while progress against ischemic heart disease, stroke, and cancer has been made in high-income countries, the same improvements have not been tracked in low-income countries.

Senior author Eve Wool, a Senior Research Manager at IHME, commented: “The global community must ensure that the lifesaving tools that have cut deaths from ischemic heart disease, stroke, cancer, and other non-communicable diseases are available to people in all countries, not just high-income ones.”