Mask Adherence and Rate of COVID-19 Across the United States

New state-by-state analysis shows a statistical association between high adherence to mask wearing and reduced rates of COVID-19 in the U.S. Charlie Fischer and colleagues at the Boston University School of Public Health in Massachusetts present these findings in the open-access journal PLOS ONE on April 14.

Analysis showed that, out of 15 states that did not require people to wear masks in public, 14 had high COVID-19 rates. Meanwhile, eight states had self-reported adherence rates of 75 percent of greater, and none of these states had a high COVID-19 rate. States with the lowest adherence rates had the greatest likelihood of high COVID-19 rates in the subsequent month.

The eight states with at least 75-percent adherence to mask wearing had a mean COVID-19 rate of 109.26 per 100,000 residents in the subsequent month, while the mean COVID-19 rate was 239.99 for states with less than 75 percent adherence.

These findings provide new evidence in support of mask-wearing as a major factor that contributes to reduced COVID-19 rates. They suggest that policies and public health efforts to reduce the spread of COVID-19 should include a focus on improved mask adherence throughout the U.S.