Mask mandates did not slow the spread of the coronavirus in the United States. A new study in pre-publication phase provides further documentation of what astute observers of the COVID-19 pandemic already know.

The study’s lead author Damian D. Guerra, an assistant professor of biology at the University of Louisville, and co-author Daniel J. Guerra, of VerEvMed, “hypothesized that statewide mask mandates and mask use are associated with lower COVID-19 case growth rates.”

Then, they set out to do what real scientists actually do: Disprove the “null hypothesis.” This is another way of saying they set out to falsify their assumption. Spoiler alert: They did.

“Contrary to our hypothesis, early mandates were not associated with lower minimum case growth,” the authors found. “Maximum case growth was the same among states with early, late, and no mandates. This indicates that mask mandates were not predictive of slower COVID-19 spread when community transmission rates were low or high.”

“We wondered if mask mandates were associated with smaller or slower surges in case growth,” the study continued. “Differences between minimum and maximum case growth were similar among early, late, and no mandate states, and surges from minimum to maximum growth occurred at similar rates. These findings suggest that mask mandates are not predictive of smaller or slower shifts from low to high case growth.”

While the study is not yet peer-reviewed, it fits with a macro-analysis of state cases. There is also a difference between mask mandates and mask usage. The study did find that mask usage correlated with lower case rates, but only with lower transmission rates.

“Case growth was not significantly different between mandate and non-mandate states at low or high transmission rates, and surges were equivocal,” the authors found. “Mask use predicted lower case growth at low, but not high transmission rates. Growth rates were comparable between states in the first and last mask use quintiles adjusted for normalized total cases early in the pandemic and unadjusted after peak Fall-Winter infections. Mask use did not predict Summer 2020 case growth for non-Northeast states or Fall-Winter 2020 growth for all continental states.”

The bottom-line conclusion for the authors: “Mask mandates and use are not associated with slower state-level COVID-19 spread during COVID-19 growth surges.”

As reported earlier at Becker News: “Mask mandates do not appear have any statistically significant effect on COVID-related case rates or death rates. Whether or not masks themselves have any marginal effect is a separate matter. A recent CDC study showed they have 0.9%-1.9% effect on case rates if used for 100 days.”