Life expectancy in the US has trailed high-income countries for a decade. The pandemic made it worse.

The coronavirus pandemic has widened the life expectancy gap between the U.S. and other high-income countries, a new study shows, and experts say it could take decades to overcome.

The life expectancy gap between the U.S. and other comparable countries already had increased from 1.88 years in 2010 to 3.05 years in 2018, according to a study published Wednesday in The BMJ, a peer-reviewed journal by the British Medical Association.

But researchers from Virginia Commonwealth University found the gap substantially increased to 4.69 years between 2018 and 2020. This decrease in life expectancy over the past two years was 8.5 times the average decrease in peer countries.

“The U.S. has experienced a massive decline in life expectancy in 2020 on a scale that hasn’t be seen since World War II,” said study author Dr. Steven Woolf, director emeritus of the Center on Society and Health at Virginia Commonwealth University in Richmond. “That’s pretty stunning and it was not experienced on that scale by other countries.”

From 2018 to 2020, U.S. men had a larger decrease in life expectancy than women, at 2.16 years versus 1.5 years. Life expectancy decreased the most among Black and Latino populations, falling by 3.25 years and 3.88 years, respectively.

“We had been making progress for some years narrowing the Black-white mortality gap. That entire progress got erased in 2020,” Woolf said. “In the Latinx population, there’s a well-known advantage the community has higher life expectancy, and that advantage was almost completely erased by the pandemic.”

The study included 16 countries in its analysis: Austria, Belgium, Denmark, Finland, France, Israel, Netherlands, New Zealand, Norway, South Korea, Portugal, Spain, Sweden, Switzerland, Taiwan, and the United Kingdom.

Countries normally included in these types of analyses – such as Germany, Italy, Australia, Japan, and Canada – were missing from the study, said Jessica Ho, assistant professor of gerontology, sociology, and spatial sciences at the University of Southern California, who was unaffiliated with the study.

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Canada is a particularly important data point, Ho said, as it has similar demographics, including indigenous populations, a shared border with the U.S. and multiple surges of coronavirus cases.

But she said including these countries in the study wouldn't have significantly changed its results, as the U.S. public health system was in bad shape long before the pandemic.

“Going in, we already expected the U.S. was going to be hit quite harder but the question was how much does it put us back," Ho said.

A country's life expectancy is shaped by its health care system, personal health behaviors, social and economic factors, physical and social environment, and public policies. Even if the U.S. fixed all these problems overnight, Ho said it would still take decades to catch up to other high-income countries.

“If we do everything perfectly, we can increase (life expectancy) 2.5 years every decade,” she said.

Even under this ideal scenario, it would have taken about 12 years for the U.S. to catch up in 2018, with the assumption other countries' life expectancy stayed the same. The pandemic knocked the U.S. back to 19 years.

But all hope is not lost, Ho said. There’s a chance U.S. life expectancy can recover in the next year. After the 1918 Spanish flu pandemic, life expectancy in men dropped to 36.6 years, but jumped back up to 53.5 the following year, according to data from the University of California, Berkeley.

“Fairly unhealthy people died during COVID whereas they might have died in 2022 or 2023 or 2024," she said, noting the setback from COVID-19 may not be permanent and that the country may bounce back.

But Woolf said a quick recovery isn’t guaranteed, as Americans continue to deal with the health and economic ramifications of COVID-19.

“The systemic factors that led to this catastrophe are the same systemic factors that caused the U.S. to fall behind other countries for many years,” he said. “And if they continue to persist, we’ll see the life of Americans continue to deteriorate compared to life in other countries.”

Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.

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This article originally appeared on USA TODAY: US life expectancy: COVID widened gap between US, other countries