Global life expectancy increased by 6.2 years from 1990 to 2021, despite a pandemic-related dip between 2019 and 2021, a new study published in The Lancet has found.
The overall rise in life expectancy worldwide over the past two decades was helped by several factors, including a decline in deaths from intestinal infections such as diarrhoea, a research team led by Simon Hay from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington said.
This decline alone was responsible for an increase of 1.1 years in life expectancy during the period.
"The second-largest effect on increasing life expectancy is attributed to the reduction in deaths from lower respiratory infection, contributing 0,9 years of gained life expectancy from 1990 to 2021," according to the study.
The researchers also cite reduced mortality from strokes and coronary heart disease as key factors for the increase in life expectancy.
Pandemic-related drop
However, with the onset of the coronavirus pandemic, life expectancy worldwide dropped by 1.6 years between 2019 and 2021 due to Covid-related deaths, the researchers found.
Depending on the region, that trend differed widely, with life expectancy in South-East Asia, East Asia and Oceania only decreasing by 0.4 years during that period, the smallest drop seen overall.
Meanwhile, life expectancy in the Caribbean and Latin America dropped by 3.6 years between 2019 and 2021, according to the researchers.
Covid among leading causes of death from 2020
Between 1990 and 2019, the most common causes of death were coronary heart disease, stroke, chronic obstructive pulmonary disease (COPD) and lower respiratory tract infections (in that order), the experts said.
However, Covid-19 occupied third place in 2020 and even moved up to second in 2021, they found.
"Our study presents a nuanced picture of the world's health," co-author Liane Ong was quoted as saying in a press release.
"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 researchers did not look at absolute global life expectancy. The World Health Organization (WHO) estimates that it rose by some 6 years between 2000 and 2019 - from 66.8 to 73.4 years.
Methodology
For their study, the research team looked at more than 56,000 data samples including autopsies, censuses and cancer registers to analyse the global impact of disease, injury and risk factors.
It is based on mortality estimates for 288 causes of death across more than 200 countries and regions.
The Covid estimates were derived from analyses of excess mortality due to the coronavirus pandemic from January 1, 2020 to December 31, 2021.
Overall, the study draws on the expertise of more than 11,000 employees from over 160 countries and territories, according to the article.
