Brown study: Stay-at-home orders slowed COVID-19 spread

PROVIDENCE — Stay-at-home orders appear to have strongly slowed the spread of COVID-19, according to research recently published in the Journal of Infectious Diseases by a Brown University team headed by epidemiologist Mark Lurie.

“Understanding the trajectory of the epidemic in the U.S. is critical, and measuring the impact of stay-at-home orders on epidemic growth offers evidence for current and future COVID-19 control and containment measures,” Lurie said in a Brown University news post.

“While this was not a randomized trial,” Lurie continued, “and therefore we cannot establish causation, what was clear in our study is that stay-at-home orders were significantly associated with slowing epidemic growth rates.”

The study, according to the Brown post, “calculated the pandemic doubling time — the amount of time it takes for the number of cases to double — on both a national level and for individual states. An increase in doubling time indicates a slowing pandemic.”

In an email to The Journal, Lurie wrote that “in states with stay-at-home orders” — and that includes Rhode Island, where the order was entered on March 28 — “the amount of time it took for the number of infections to double was about twice as long as in states without stay-at-home orders.

Said Joe Silva, a doctoral student at Brown’s School of Public Health: “This study does not imply stay-at-home orders were the sole factor that drove the observed increase in epidemic doubling time, but the data may be representative of the impact of multiple public-health measures.”

Silva added: “Our study period included data through the end of April, and since then cases have increased beyond what was previously thought to be the peak of the pandemic within our borders. During this time, states have also removed stay-at-home orders, and it will be just as important to study the potential impacts on disease spread after these measures were no longer in place.”

Lurie and Silva were lead co-authors of the study, conducted by researchers at Brown’s School of Public Health and the Warren Alpert School of Medicine. Rachel R. Yorlets, Jun Tao and Philip A. Chan also contributed.