The new study carefully examines the changes in the growth rates of Covid-19 cases and deaths in counties before and after masking mandates were issued by the state and restaurant restaurants were allowed from March to December last year.
The researchers found that requiring people to wear a mask outside their home or in retail establishments and restaurants from March 1 to December 31, to a 0.5 percentage point decrease in the daily growth rate of Covid-19 cases up to 20 days after the mask mandate has been implemented. Decreases to 1.8 percentage points were seen up to 100 days later.
Mask mandates were associated with a 0.7 percentage point decrease in the daily mortality rate of Covid-19 up to 20 days after implementation and a decrease of up to 1.9 percentage points respectively up to 100 days later, the researchers found.
According to the study, changes in daily growth rates for Covid-19 cases and deaths were not statistically significant, until 40 days after the restrictions were lifted.
But the admission of restaurant owners is related to increases of 0.9, 1.2 and 1.1 percentage points in cases to 60, 80 and 100 days respectively after the restrictions were lifted, the researchers found. The provision of meals on the premises was accompanied by increases in Covid-19 mortality rate from 61 to 80 and 81 to 100 days, respectively by 2.2 and 3 percentage points after restrictions were lifted.
The study did not cover other Covid-19 safety measures in provinces and states that could affect the data, and the analysis did not distinguish between indoor and outdoor eateries.
“Mask orders and the restriction of any meals at restaurants can help reduce the transmission of COVID-19 in the community and reduce the growth rates of cases and deaths,” researchers from the CDC and the University of Nevada wrote in the paper. “These findings could inform public policies to reduce the spread of COVID-19 in the community.”