Greater access to high-speed internet reduced Covid-19 deaths in the US, according to a new analysis that underscores the importance of digital connectivity for public health.

A 1% increase in broadband access nationwide lowered Covid-19 mortality by about 19 deaths per 100,000, found researchers at Digital Planet, a research initiative at The Fletcher School at Tufts University.

“The internet may have been even more important in the pandemic than initially understood — for some, it was literally a matter of life and death,” the researchers wrote.

Broadband made an even bigger difference in metro areas. In urban counties, a 1% rise in broadband access lowered Covid deaths by 36 per 100,000, the analysis said.

But researchers found that broadband access didn’t have a significant impact on Covid-19 mortality rates in rural areas.

That’s noteworthy because states are in the midst of drafting proposals for a share of $65 billion allocated to broadband internet under last year’s bipartisan infrastructure law.

The current federal broadband-equity program favors rural areas that lack broadband infrastructure, said Bhaskar Chakravorti, founder of Digital Planet and dean of global business at The Fletcher School. But a bigger problem is in urban areas, such as Chicago, where there are many more people without adequate broadband access. “We should be covering more people, not covering more miles,” said Chakravorti.

Poverty is strongly correlated with lack of broadband internet, which is typically expensive. The US has the second-highest broadband costs among 35 countries, according to the Organization for Economic Cooperation and Development.

But even when controlling for socioeconomic factors such as income and education, Digital Planet still found more broadband access resulted in fewer Covid-19 deaths.

The average rate of broadband availability per county in the US is 76%, but even where broadband is technologically available, people don’t necessarily have access to use it. Average broadband usage across US counties is just 39%, the Digital Planet researchers noted.

The fact that so many people in areas with broadband infrastructure still can’t use high-speed internet was an “aha” moment, Chakravorti said, suggesting that “the primary challenge that needs to be addressed is one of affordability.”

The Federal Communications Commission defines broadband as minimum internet speeds of 25 megabits per second for downloads, though by some standards this is considered slow.

The Digital Planet analysis spanned January 2020 through February 2021, before Covid-19 vaccines became widely available. Researchers didn’t examine dynamics related to vaccines, such as misinformation, conspiracy theories or the use of online registration for immunization.