Cell phone location used to estimate COVID-19 growth rates

Cell phone location data shows that in counties where activity declined at workplaces and increased at home, coronavirus infection rates were lower.

New research shows that counties with a greater decline in workplace cell phone activity during stay-at-home orders showed a lower rate of COVID-19 infections. The researchers believe patterns they saw in publicly available cell phone location data could be used to better estimate COVID-19 growth rates and inform decision-making when it comes to shutdowns and “reopenings.” This research was published in JAMA Internal Medicine.

hand holding a smartphone in a public transit station tracking human images on the screen in red or green indicating covid exposure


“It is our hope that counties might be able to incorporate these publicly available cell phone data to help guide policies regarding reopening throughout different stages of the pandemic,” says the study’s senior author, Joshua Baker, an assistant professor of medicine and epidemiology. “Further, this analysis supports the incorporation of anonymized cell phone location data into modeling strategies to predict at-risk counties across the U.S. before outbreaks become too great.”

Baker and the other researchers, including the study’s lead author Shiv T. Sehra, an assistant professor of medicine at the Harvard Medical School, used location data from cell phones—which were de-identified and made publicly available by Google—to analyze activity across up to 2,740 counties in the United States between early January and early May 2020. This data was broken up into locations where the activity took place, ranging from workplaces, to homes, retail stores, grocery stores, parks, and transit stations.

They saw that in counties where there was initially a higher density of cases, visits to workplaces, as well as retail locations and transit stations, fell more sharply than counties less affected by COVID-19. At the same time, in these counties, there was a more prominent spike in activity at homes.

This story is by Frank Otto. Read more at Penn Medicine News.