The most rigorous and comprehensive analysis of scientific studies conducted on the efficacy of masks for reducing the spread of respiratory illnesses — including Covid-19 — was published late last month. Its conclusions, said Tom Jefferson, the Oxford epidemiologist who is its lead author, were unambiguous.
“There is just no evidence that they” — masks — “make any difference,” he told the journalist Maryanne Demasi. “Full stop.”
I've gotten a couple of emails asking me what I think of this. Luckily, I can tell you: not much.
When this study first came out I planned to write a post about it. But then I read through the whole thing (here) and discovered that although it reviewed 13 mask studies, only two of them were for COVID-19. All the others were pre-2020 studies of how well masks worked for various other respiratory diseases. The two COVID masking studies produced the following results:
- Bangladesh: "Villages where in-person reinforcement of mask wearing occurred also showed a reduction in reporting COVID-like illness [about 10% overall, 35% among the elderly]."
- Denmark: "Although the difference observed was not statistically significant, the 95% CIs are compatible with a 46% reduction to a 23% increase in infection."
These are not spectacular results, but neither are they zero results. Nor are these the only two masking studies ever done on COVID.
Overall, this report didn't change my priors much: masks are a good-but-not-great intervention that helps limit the spread of COVID. They are mostly helpful (a) in crowded indoor settings and (b) when used properly. Cloth masks, as near as I can tell, are all but useless. However, surgical masks—especially N95 masks—are helpful. The greater the percentage of people who wear them, the more helpful they become.
A summary of masking studies specifically for COVID is maintained by the CDC here. The results vary, and don't generally show huge benefits from wearing masks, but they do mostly show benefits.
I wore a mask like was suggested, when it was suggested. I happily stopped when no longer required (two years of partially fogged glasses made me crazy). Probably, I would guess, like most people. The militantly unmasked and the people who don't want to give up their masks are the annoying people we should bar from holding public office.
"and the people who don't want to give up their masks are the annoying people"
I've rather enjoyed not being sick for the past three years, so I'll keep wearing a mask in airports etc.--not sure what annoys you about that.
Start making more money weekly. This is valuable part time work for everyone. The best part ,work from the comfort of your house and get paid from $10k-$20k each week . Start today and have your first cash at the end of this week. Visit this article
for more details.. https://createmaxwealth.blogspot.com
I have a 5 year old so its a losing battle but I a still wear a mask in indoor public spaces because I want to get sick less.
The annoyance at mask wearers is hard to understand.
Imagine getting frustrated at people who wear a seat belt or those who dont drive drunk.
Is it guilt? Insecurity?
definitely odd.
I thought it was rather contradictory--Stephens said masks might be effective on an individual basis, but mask mandates were not. If the first is true, it would seem that Americans just don't use masks, or use them well. Given all the controversy, I tend to trust the physics of masks. At my age, I need all the edge I can get.
Right. Stephens maks a common error, primarily by misinterpreting some of the words he read in the report. Effectiveness of mask mandates is the product of three factors--(1) how well a proper, and properly worn, mask can protect the wearer; (2) how many of the wearers are wearing proper masks, and wearing them properly; and (3) how many of the mask wearers are wearing them specifically (and only) because of the mandates.
So he jumps to a ridiculous conclusion--masks don't work--because the statistics indicate mask mandates don't significantly impact the Covid data.
I don't respect people who whine about masks. Masks are at worst mildly uncomfortable. They are cheap and harmless. Stephens' hyperventilating about "physical, psychological, pedagogical and political costs" is juvenile. Even if we weren't sure whether they helped or not, mandating them was still the right thing to do.
Now that hospitals are not being overwhelmed and Covid has gone from public health emergency to ordinary public health problem, I've stopped masking, but I still have no respect for the whiners. Stephens' claim that they were "right" is BS even if it turns out that masks didn't help, because *they couldn't have known that at the time*, they were making it up for selfish, stupid reasons. No society can hope to survive for long if it respects people who refuse to do their part in a public emergency.
It's also a little rich for people who whined and screamed and threw a fit for years about masking and thereby undermined its efficacy by encouraging people not to do it to now turn around and say "Just as I thought--it doesn't even work!"
Yup. Eff Stephens.
This pandemic really showed that the right has become selfish assholes.
Their behavior is not selfish. They deliberately exposed themselves to infection, by not getting vaccinated if not by refusing to wear masks, for the sake of signaling group solidarity - specifically racial and religious groups. If low-income MAGAs considered their own individual best welfare they wouldn't vote for the party that is opposed to their economic interests. They don't even put the actual interests of their own group first when part of belonging means rejecting sound medical advice.
Group loyalty very often transcends selfishness among social animals.
The "solidarity" of the MAGA group IS their selfishness. Not to mention wounded privilege, jealousy, self-image as victims, hatred of non in-groupers, and violence.
I used to read "Sorry, Antivaxxer" for a sense of schadenfreude. I eventually found myself feeling sorry for the poor MAGAts, as the Omicron varient ripped through whole unvaccinated families. A surprising number, as they lay struggling to draw their last breaths, pathetically admitted they had been wrong and all the right-wing BS about Covid, Covid cures and vaccinations was just that, BS.
You really need to test a number of masks and mask sizes. There are huge variants in shape, size, and anchoring bands. I found the "standard" paper N95 masks worked sort of OK for my face once I found some larger sized ones. But my wife has a longer skull front to back and the elastic straps were extremely uncomfortable on her ears, There are also problems if you can get a good seal over your nose - so some masks have formable metal strips to improve the seal. It's also a problem if the mask plasters against your nostrils and mouth. That can get funky pretty quickly because the moisture from your breath saturates the paper.
We finally found some KN95 masks with the metal strips AND some structural integrity that holds the mask far enough from your nostrils to reduce the moisture sogging problem quite a bit. The bottom of the mask also comes around well under your chin, reducing forward leakage. The "duck" masks also appear to have a nice distance between nostrils and mouth and the front of the mask and well under the chin.
True medical grade masks for use with highly contagious patients are custom fitted and require VERY careful sealing. They are also hugely expensive and require some help and training to make sure they fully seal down. Not fun!
My wife and I have made it from late 2019 through now with no COVID or Flu attacks. And we made full use of the free COVID tests whenever we were unsure to make sure we were not infected, despite having to navigate some crowded scenes to get supplied.
Almost all Americans who used a mask wore cloth masks where a 2015 study showed that 97% of the flu virus load penetrated the mask. With surgical masks, still 50% goes through.
Masks were no more than a religious talisman and health officials new this which is why the WHO advised against them for H1N1 in 2009.
I mean will Stephens request that at his next surgical procedure the surgeons don't wear masks?
It would be useful to know - but probably very difficult to discover; do masks mostly prevent infected people from spreading covid? Or prevent the uninfected from getting it? Or both about the same?
Don't we have technology to give better answers to this question than we have gotten so far? Why not 'instrument' masks with 'virus traps', inside and outside, and analyze and compare amounts captured after a day's use? Microelectronics to monitor actual use time? Regular testing of participants for infection?
At how many dollars a mask for the virus traps and analysis?
If the instrumentation is reasonably accurate, you don't need tens of thousands of wearers to conduct an effectiveness study.
It would be useful to know - but probably very difficult to discover; do masks mostly prevent infected people from spreading covid? Or prevent the uninfected from getting it? Or both about the same?
I'm under the impression it's the former, at least with non-N95 masks. Masking as a general policy is a "herd effect" strategy. If you're wearing a lower grade mask, the protection you enjoy is quite modest unless most of the people around you are likewise doing so.
I think the current consensus is that it reduces your chances of getting sick somewhat but is most useful so you don't get others sick.
Stephens was also vehemently a global warming denier. Then he took a trip to Greenland. Maybe he needs a trip to an ICU?
Pretty much everything you need to know about the paper is in this author conclusion:
"The high risk of bias in the trials, variation in outcome measurement, and relatively low adherence with the interventions during the studies hampers drawing firm conclusions."
(That's on top of the objections Kevin rightly points out.)
The quote Stephens pulls out of Jefferson saying "masks make no difference" is typical scientist speak for 'I want the publicity for my study, so I'm going to say something wildly provocative to get in the news'. (He says as someone who's participated in enough science press releases to recognize when someone is going for the click bait.) The conclusion of the report is that there is no strong evidence that masks *made* a difference. But as usual, absence of evidence isn't evidence of absence.
And as others above have pointed out, even if masking as practiced in reality didn't make a huge difference, you don't get to shout at people for two years "act like a dumbass", and then later claim, "see, nothing would have made a difference!"
And even if masking only made a small difference, what fraction of 1 million dead would have been 'too small' to be worth the `burden' of masking?
So, no, I'm not going to apologize to Stephens and his friends. He's still a first class idiot that needs a remedial science education.
>> what fraction of 1 million dead would have been 'too small' to be worth the `burden' of masking?<<
Florida got rid of mask mandates and other precautions and opened up for business quickly. California shut down quickly and opened up for business much later. If Florida had California’s COVID death rate more than 25,000 Floridians would still be alive today. I suppose that kind of answers your question, right? About 1,400 deaths per million.
You can't make that straight of a comparison. Florida has a lot more old people who are are more likely to die if they contract covid. Also, the extreme heat for 6-8 months a year means people are inside in enclosed areas (with air conditioning) for much of time. The temperate clime in CA means people spend a lot more time outside for a good part of the year. I'm sure there a hundred other variables but those are the two big ones that come to mind.
You can't use "prior" as a noun, it's an adjective. Say "prior convictions" or whatever but mostly remember that it's not an idiom used by 99.9% of people.
"Prior" is a commonly-used noun in statistics.
Merriam-Webster
prior
1 of 2
"adjective"
pri·or ˈprī(-ə)r
Synonyms of prior
1
: earlier in time or order
2
: taking precedence (as in importance)
priorly adverb
prior
2 of 2
"noun"
pluralpriors
1
a
: the superior ranking next to the abbot of a monastery
b
: the superior of a house or group of houses of any of various religious communities
2
US law enforcement, informal : a previous instance of arrest or conviction for a crime
He had been told that burglary, like auto theft, rarely drew a state prison term, unless you had lots of priors.
—Joseph Wambaugh
From Wikipedia:
"A prior probability distribution, often simply called the prior, of an uncertain quantity is the probability distribution that would express one's beliefs about this quantity before some evidence is taken into account."
I’ve seen the way people wear masks. Given the huge number that wear them below their nose, I’m not at all surprised it’s hard to get a statistically significant disease reduction in a large population.
That tells me absolutely nothing about the effectiveness of my properly-fitted, properly-worn N95 in situations where I’m spending hours in a crowd.
Yikes...what a terribly misleading article by Stephens. The NYT is an atrocious newspaper. Not Fox level bad, but pretty terrible.
I wouldn't generalize to the entire paper based on one bad op-ed. I definitely respect Stephens less after reading this. Hopefully they will publish a counterpoint piece.
Yah, but the old Grey Lady got the weapons of mass destruction wrong. And the buttery males. And the Russian interference in our election. And their coinvestigation (with Breitbart!!) of the Clinton foundation. Not to mention their years long refusal to use the L-word to describe statements by Trump, and their hiring of a light weight like Bret Stephens as their "in house conservative" to demonstrate their balance.
In looking at the study Leanna Wen noted that it says masks don't help at a population level if most of the population doesn't use them.
Thanks for your analysis and comments, Kevin.
My takeaway from the study: mask mandates don’t work in countries where a significant percentage of the population don’t want to wear masks. That would include the U.S.
I wonder what the results would be for a study done in Japan and South Korea where virtually the entire population followed the mandate —— hundreds of thousands of people didn’t die.
Cloth masks are NOT useless. They block direct inhalation of droplets or cause them to coalesce so they are less likely to make it deep into your system. Research has shown they are something like 50-70% effective at blocking inhalation when worn PROPERLY. I'd say about a third of the mask-wearers I've seen over the years are not covering their noses, which renders ANY mask 0% effective.
I've been wearing 2-layer cloth masks since the beginning and have made it through the whole pandemic without getting infected (so far). Maybe I'm just lucky. Maybe I had an asymptomatic infection. But I am pretty sure that the masking helped.
The cloth masks were also pretty much the only thing available in early 2020 as the mask mandates went in. It turns out that medical establishments go through VAST numbers of masks per day and had (along with a lot of other industries) gone into just-in-time delivery. Which is great if your supply chain is running perfectly. Not so good if any stress hits.
The day after the mask mandates went down, there wasn't a medical grade mask to be had in Whatcom county. Hardware stores were stripped of sanding and painting masks - if the still had any - a lot of them donated their supplies of anything remotely useful to the local hospitals and clinics.
And . . . whaddya know? Vox has a whole article about this:
https://www.vox.com/future-perfect/2023/2/22/23609499/masks-covid-coronavirus-cochrane-review-pandemic-science-studies-infection
Read it.
When 50% of people aren't wearing masks and 90% of those with masks are wearing them incorrectly it is not surprising they were relatively ineffective. However, many of us felt the tiny inconvenience was worth possibly preventing some infections and even some deaths. Those complaining about wearing masks are evil morons, full stop.
And furthermore! . . . (he shouts with a wag of the finger) . . . there is a BIG difference between an actual laboratory test to physically determine how efficiently a mask material can filter out virus-like particles and some lazy sitting-in-front-of-a-computer project that analyzes online stats to purportedly judge the effectiveness of TELLING people to wear masks.
The danger of the latter type of study is that it may conclude, as this one did, that ADVISING people to wear masks is not effective, and so an INDIVIDUAL may conclude that WEARING a mask is not effective. This is not only wrong but dangerous.
Yeah, I'm taking Stephen's advice next day I do a tour in my MICU, no masks. Hopefully I'll make it.
Seriously though, that guy can find a corner and ball his little, delicate fist up and smash his groin until he is unconscious. The misrepresentation of this study would make the Pope angry enough to kick a hole in some stained glass at the Sistine Chapel. Also screw that guy for his contrarianism of climate science.
Let's settle this once and for all. Two hospitals:
A. Zero masks by staff and patients.
B. Masked per usual.
I challenge anyone who claims masks are fairly useless, to propose this study. If you don't have the balls to do it, then you have to STFU from here on out about mask efficacy.
I think what the study implied was that while surgeons may wear masks (usually doubled-up, in fact) with great care and precision in the OR, most people were, whether intentionally or not, half-assing masking protocols during the pandemic. Individuals may have provided themselves some protection, but apparently in the aggregate it didn't make much difference. The real comparison would be between a hospital where doctors followed surgical masking protocols to a T, and another where surgeons and nurses just kind threw whatever over their mouths or under their noses and went to work. I know that I often was probably just going through the motions with a gappy-sided medical mask a lot of times when I really should have been wearing a fitted N95 respirator.
The conclusion, however, was that masks did not make a difference.
So, a hospital that maintained its current protocols, even if sloppy adherence, should still have the same outcome as one that did not use masks at all, according to the authors of the study.
Protect yourself and your loved ones as much as you can (safety doesn't exist and is a theory not actually found in the real world) and let the right-wing authoritarians poison each other.
Eat right, exercise, avoid fascists, and vote.
Repeat.
BTW, that study's lead author also says that SARS-CoV-2 did not come from China.
Just saying, maybe Bret Stephens ought to go work in a BSL-3 facility on a more lethal SARS without a mask and report back to us. I think it's a good idea for anti-maskers to prove to us the level of commitment to their dogma, don't you?
It is also a population level analysis which doesn't say anything directly about individual results. And this is pretty obviously a difficult thing to do a controlled experiment with.
A number of commentors here have mentioned incorrect wearing. Given the enormous volume, couldn't we have had a cheap (because economies of scale) chip embedded in every mask that would signal correct/incorrect fit? Pressure sensor detecting respiration-synced pressure swings when the mask is fitted without leakage? Could double as end-of-life indicator by differential pressure rise? Powered by piezoelectrics, as mask flexes?
Here is a critique of the Cochrane Report.
Also, Stephens is a dishonest rightwing chaos agent.
https://theconversation.com/yes-masks-reduce-the-risk-of-spreading-covid-despite-a-review-saying-they-dont-198992
There have been a number of lab studies on masks and in those studies masks work to reduce risk. They arent force fields, preventing 100% of infections, but they do reduce risk. So there is no question about whether or not masks work, they do. What you are assessing when you do a study is look at compliance so of course you expect a lot of variability in studies. The take home is that individuals should know that if they wear a mask properly and reliably they can reduce risk.
My caveat would be that the new variants have been incredibly infectious so your protection from lower level masks is minimal unless you can keep exposures very short. You need to use an N-95.
Steve
You need to use an N-95.
Yes, I think this is correct, especially given the sporadic and uneven nature of masking in most places these days. A lower grade mask isn't going to do you much good when only 30% of the people at Trader Joe's are properly wearing one.
Nearly all the points made here appear in the comments section of the original article, and some of them have the authoritative sound of a professional.
I doubt anyone at TFN will read them, much less address them; M. le Duc least of all.
So, basically Stephens is conflating (either stupidly or on purpose; it's always hard to tell with him) mask mandates with masking in general? Does that sound about right?
Relatedly, I recall hearing early in the pandemic that masking might confer a "reduced virion particle load" effect. That is, wearing a mask may protect you from an infection or it may mean that any infection you get is milder, due to a lower viral load. Is there something to this? I suspect here in China the very widespread masking I see—nearly three months after the end of Zero Covid—accounts for the relatively light toll that the late autumn/winter surge has taken. And yes, it's difficult to parse exactly what's going on—and the government death statistics obviously aren't remotely reliable. But my sense from living here, having numerous Chinese friends, colleagues, etc—and from travel (just got back from a trip down the east coast) is that the China has gotten off relatively lightly (even if not as lightly as government statistics would have you believe).
And I wonder if perhaps widespread masking has something to do with it...