The first large, randomized controlled trial of its kind showed no statistically significant difference in COVID-19 cases between people who wore masks and those who did not.
The Danish study published this week in the Annals of Internal Medicine found that a “recommendation to wear a surgical mask when outside the home among others did not reduce, at conventional levels of statistical significance, incident [COVID-19] infection compared with no mask recommendation.”
Among 6,000 participants in Denmark, half were told to wear masks and half were not. The researchers found 42 of the participants who were told to wear masks contracted COVID-19, while 53 in the control group got the disease.
The authors concluded the difference was not statistically significant.
Critics of the study argue the researchers did not investigate specifically whether masks prevented people infected with COVID-19 from infecting other people.
A Danish newspaper reported the mask study had been completed three months ago, but it was rejected by leading three medical journals because the results are controversial.
The Blaze noted that prior to changing its position on universal mask-wearing, the Centers for Disease Control cited 10 randomized controlled trials that showed “no significant reduction in influenza transmission with the use of face masks.”
In October, an analysis of a dozen graphs charting the number of COVID-19 cases in countries and U.S. states confirmed the conclusions of recent studies that mask mandates have no effect on the spread of the disease.
Meanwhile, Pennsylvania on Tuesday imposed new COVID-19 restrictions that will require wearing masks in homes if someone from outside a household is present, even if physical distance can be maintained.
“Wearing a mask is really one of the simplest steps we can take to stop the spread of COVID-19,” she said.
About 40 states have implemented mask requirements of some sort, according to a database maintained by the New York Times.
In Wisconsin, Democratic Gov. Tony Evers announced Wednesday that he will sign an executive order extending the state’s mask mandate into 2021.
Former Vice President Joe Biden is urging Americans to wear a mask, claiming it could save at least 100,000 lives until Inauguration Day, Jan. 20.
Rejected by three journals
The Danish paper Berlingske reported the study was rejected by the Lancet, the New England Journal of Medicine and the American Medical Association’s journal JAMA.
According to the Danish newspaper @berlingske tre scientific journals have refused to publish the results of the first major scientific investigation the effect of use of masks during the Covid-19 pandemic. Apparently because the results might not show what is politically correct pic.twitter.com/OJ6ZRq8idp
— Lars Christensen (@MaMoMVPY) October 21, 2020
Former New York Times reporter Alex Berenson, who has reported extensively on the coronavirus, wrote in an Oct. 18 tweet that he had corresponded with the lead researcher in the Danish study, Thomas Lars Benfield.
He asked Benfield when the study would be published.
The researcher’s answer was: “as soon as a journal is brave enough.”
A lead investigator on the Danish mask study – the ONLY (as far as I know) randomized trial to see if masks protect from #COVID – was asked when it would be published.
His answer: “as soon as a journal is brave enough.”
If you think that means the study shows masks work… pic.twitter.com/tm5PFBa5TL
— Alex Berenson (@AlexBerenson) October 18, 2020
The editor in chief of Annals of Internal Medicine, Dr. Christine Laine, said the Danish study did a good job of answering the specific question of whether or not face masks protect wearers from COVID-19 in areas with low infection rates and high levels of social distancing, Forbes reported.
“It did not answer the question about whether widespread masking mitigates SARS-CoV-2 infection,” she says, adding that while there were concerns over misinterpretation, the editors agreed publishing it was important because it was “the only randomized control trial of masks for SARS-CoV-2 infection that has been done to date” and it was a “well-designed study.”
Forbes reported that while the study found little evidence that masks protected the wearers from Covid-19, it should not be used as evidence to not wear a mask, according the “lead author” of the study, Dr. Henning Bundgaard, professor of cardiology at Rigshospitalet in Denmark.
“Even a small degree of protection is worth using the face masks, because you are protecting yourself against a potentially life-threatening disease,” he said.
In a reponse to the study also published by the journal, Dr. Tom Frieden, former director for the Centers for Disease Control, contended the authors used antibody tests to diagnose cases of COVID-19, which could have led to a significant number of false positives.
He also argued the authors did not ensure that people who were told to wear masks wore them correctly or at all times.
Bundgaard replied, insisting the compliance rate was still “considerably better” in the study compared to regular society.
While agreeing it was possible that the antibody tests could have led to false positives, he reasoned that the “risk is in both groups, and that would probably even it out.”