For many Americans, wearing a mask has become a relic.but Finding As for the mask, it doesn’t seem to be.
Masking is widely recognized as one of the best COVID precautions people can take. Yet there is a constant debate raging about mandates, what masks should be worn, and even how they should be worn.a new review and metaanalysis ‘s masking study suggests that detractors may have a point. The paper, a rigorous evaluation of 78 studies, was published by Cochrane, an independent policy agency famous for its reviews. The review authors found “little or no” evidence that masks reduce COVID transmission at the population level and concluded that there is “uncertainty about the effectiveness of face masks.” This was also true when participants compared surgical masks to N95 masks and surgical masks to nothing.
On Twitter, longtime critics of masking and ordering put this up as the proof they’ve been waiting for. Washington Free Beacona conservative outlet cited a researcher who called the analysis “the scientific nail in the coffin of mask mandates.” Used by vaccine skeptic Robert Malone to object What he called a “self-proclaimed ‘expert'” on masking. Some researchers more subtle interpretationindicate Restrictions on review methods Therefore, it was difficult to draw firm conclusions. Even CDC director Rochelle Walensky pushed back to paper Congressional testimony this week cites the small sample size of COVID-specific studies. But the fact that the battle continues reveals that there are still no firm answers among the pandemic’s most important questions: How effective are masks in stopping COVID?
An important feature of Cochrane reviews is that they consider only ‘randomised controlled trials’. a particular type of research Because it compares the effects of one intervention to another while tightly controlling for biases and confounding variables. The trial considered in the review compared a masked group with a nonmasked group to estimate how effective the mask was in slowing the spread of his COVID in the general population. Population level details are important. everyone Wearing a mask makes a difference in spreading the virus. different from the effect of individual Masking being better studied. After all, doctors routinely wear masks when around sick patients, and they don’t seem to get infected more often than anyone else. Jennifer, an epidemiologist at Brown University “There is considerable evidence that masks can protect wearers,” Nuzzo said.
Research on individual masking generally shows what we’ve come to expect. A quality mask, when worn correctly, provides a physical barrier between the wearer and infectious particles.For example, in one study, N95 masks were Blocks 57-90% of particles, depending on how well they fit.cloth and surgical mask less effectiveIt should be noted that much of that support comes from laboratory and observational studies and does not account for real-life messiness.
Just because a Cochrane review reasonably disputes the efficacy of population-level masking does not mean that the results of previous studies supporting masking are controversial. common theme in criticism The main reason for this review is that only a small number of studies were considered due to Cochrane criteria. There are not many randomized controlled trials on COVID and masks. other Respiratory disease, i.e. influenza. While there may be some similarities between viruses, Nuzzo explained on twitterCOVID-specific trials are ideal.
The few trials in COVID-focused reviews have not shown strong support for masking. From Bangladeshwhich examined both cloth and surgical masks, found a 9% reduction in symptomatic cases in the masked and unmasked groups (and re-analysis Among the studies, there were signs of bias in the way the data were collected and interpreted).from another Denmarksuggested that surgical masks do not provide any statistically significant protection.
Criticism of the review has postulated that if more and better quality studies had been available, different conclusions might have been reached. “The low to moderate certainty of the evidence indicates limited confidence in the effect estimates. It means that the true effect may differ from the observed effect estimate,” they concluded. If it works well at your level, it makes sense that a quality mask worn properly by many people in any situation would actually provide some protection.
The review’s lead author, Tom Jefferson, did not respond to a request for comment. a recent interview Of the controversy, he backed the practical implications of the new study.
In the early stages of a pandemic, it is difficult to square all this uncertainty with masking and mandate support. Nuzzo acknowledged that the evidence was thin in the early days of the pandemic, but health officials had to act. The infection rate was high and the cost of masking was seen as low. It wasn’t immediately apparent how inconvenient and unwieldy masks can be, especially in settings such as schools. Nuzzo wears masks even in high-risk environments. “Will it keep me from getting COVID? No,” she said, but it reduces her risk — and that’s enough.
What is most frustrating about this masking uncertainty is that the pandemic has provided the United States with many opportunities to gather stronger data on the impact of population-level masking, even though those studies have not been conducted. The masking policy was based on sound but limited data. When such decisions are made, “we need to continuously evaluate whether those assumptions are correct,” he said, Nuzzo said. collect massive data To prepare for everything that could go wrong with a shuttle launch. Unfortunately she said “no Houston for the pandemic”.
It’s not easy, but it’s possible to get stronger data. A major challenge in studying the impact of population-level masking in the real world is that people are not good at wearing masks. This, of course, is also a question of mask effectiveness. However, in the real world, people generally want to remove their masks as much as possible because they are a poor fit and slip off the nose.
Ideally, the research needed to gather strong data on masks and other lingering pandemic issues would be conducted through governments. For example, the UK provides a lot of money. Randomized controlled trial of COVID drugs such as molnupiravir. So far, that doesn’t appear to be happening in the United States. None of the new research on masking included in the Cochrane review was funded by the United States government. The fact that we have never really set up a study for is a failure,” Nuzzo said. What the CDC can do is organize and fund research networks to study COVID. This is much like the Centers of Excellence the agency has in areas such as food safety and tuberculosis.
The window of opportunity has not yet closed. For all its controversy, the Cochrane review reminds us that more research on masking is needed simply to address whether pro-mask policies justify the outrage they incite. You would think policy makers would find that support a priority. “If you’re going to burn your own political capital, I wish I had proof that it was necessary,” he said, Nuzzo.
At this point, even with the strongest possible evidence, it’s unlikely to change some people’s behavior, given how politicized the debate over masks is. We are unprepared for the next virus outbreak (COVID or otherwise) because there is no virus. Although the risk remains low, bird flu shows troubling signs that it can be transmitted from animals to humans. If so, should authorities tell everyone to wear masks? Nuzzo said it has been a missed opportunity that America has never collected good evidence of the effectiveness of population-level masking on COVID. before being asked.
