In [a] large, randomized study published [November 18] in the Annals of Internal Medicine, researchers observed more than 6,000 people in Denmark from April to June when mask-wearing was not required in the country. Fewer people in the group that was advised to wear masks contracted the virus — or about a 14 percent reduced risk because of mask-wearing — but the difference was not statistically significant, indicating that the recommendation to wear the medical masks issued was not particularly effective at preventing the wearers from being infected.
…[Author Henning] Bundgaard said even the small risk reduction that masks offer “is very important, considering it is a life-threatening disease.”
That’s not how conservative circles interpreted the study. Online, commentators and elected officials who have argued against mandating masks construed that the results supported their beliefs. Even before the paper was published, the search term “Danish mask study” spiked on Google as an unfounded theory had spread that other credible scientific journals had declined to publish the research because liberal scientists were keeping the study under wraps.
“Because the issue has become so politicized, there’s a real risk — and it’s already being used in this way — that studies like this will be sort of cherry-picked and presented as conclusive evidence that masks are completely ineffective,” Columbia University virologist Angela Rasmussen said.