The new study examines the changes in the growth rates of Covid-19 cases and deaths in counties before and after state-issued mask mandates were implemented and dining in restaurants was allowed from March to December last year.
The researchers found that, from March 1 to December 31, requiring people to wear a mask outdoors or in stores and restaurants was linked to a 0.5 percentage point decrease in the daily growth rate of Covid-19 cases up to 20 days after that. the mask mandate was implemented. Reductions of up to 1.8 percentage points were observed up to 100 days later.
Mask mandates were associated with a 0.7 percentage point decrease in Covid-19 daily death rates up to 20 days after implementation and a decrease to 1.9 percentage points up to 100 days later, respectively, the researchers found.
According to the study, changes in daily growth rates for Covid-19 cases and restaurant deaths for restaurants were not statistically significant until 40 days after the restrictions were lifted.
But allowing on-site restaurant dining was associated with an increase of 0.9, 1.2 and 1.1 percentage points in cases up to 60, 80 and 100 days, respectively, after the restrictions were lifted, the researchers found. Allowing on-site dining was associated with a 2.2 and 3 percentage point increase in the death rate from Covid-19, 61 to 80 and 81 to 100 days, respectively, after the restrictions were lifted.
The study did not check for other Covid-19 safety measures in counties and states that could have affected the data, and the analysis did not differentiate between eating indoors and outdoors.
“Mask mandates and curbing on-site dining in restaurants can help limit community transmission of COVID-19 and reduce the growth in the number of cases and deaths,” researchers from the CDC and the University of Nevada wrote in the paper . “These findings could inform government policy to reduce the spread of COVID-19 in the community.”