Q&A: Examining the leading causes of death globally
Published April 3, 2024
The COVID-19 pandemic had a profound impact on health trends in 2020 and 2021, becoming the second-leading cause of death around the world. Dr. Mohsen Naghavi shares these findings and more from the latest Global Burden of Disease study.
This transcript has been lightly edited for clarity
How has life expectancy changed from 1990 through 2021?
We find that from 1990 until 2019, for the whole population of the world, we increased life expectancy in these 30 years by around 7.8 years. That was very good. But, after 2019, 2020, and 2021, with the pandemic starting and with increasing COVID, we not only lost 1.6 years from our life expectancy, but around 12 million deaths happened directly due to COVID and 4 million due to pandemic-related causes.
And if we didn’t have COVID, we would have had had 8.4 years of increase in life expectancy from 1990 until 2021.
What factors contributed to the global increase in life expectancy?
The main factor [in this increase] was decreasing mortality and prevention of the incidence of diarrhea. With decreasing mortality and the preventive processes that we had in the world in these 30 years, we added 1.1 years to life expectancy. We had a 0.9-year increased life expectancy due to better control of lower respiratory infections, 0.7 years for better control of stroke, and 0.6 years for ischemic heart disease and cancer in increased life expectancy.
How did the rankings of cause of death change over the period 1990-2021?
There is something surprising and there is not. First, from 1990 until 2019, the top three killers in the world were ischemic heart disease, stroke, and COPD, or chronic obstructive pulmonary disease. They were the top three in the world for 30 years. With the COVID pandemic, COVID in 2020 became the second cause. It was ischemic heart disease, COVID, stroke, and COPD. And in 2021, COVID went to the top. It was COVID, ischemic heart disease, stroke, and COPD. Overall, there were not any other big changes due to the pandemic, or if there were, it was very local.
These are not global changes except for lower respiratory infections. Non-COVID lower respiratory infections in this duration of the pandemic decreased a little.