[timr]

> You will find literally zero papers credibly claiming otherwise.

Of the papers cited in the WHO meta-analysis of face masks and infection [1], all of the (three!) papers from a non-health-care setting had a confidence interval overlapping 1.0 (i.e. "no benefit"). Of those in a health-care setting, about half had confidence intervals overlapping 1.0 (i.e. "no benefit"):

https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

The literature in this area was exceptionally ambiguous prior to 2020, and hasn't improved over the course of the pandemic. You've just made a provably incorrect claim. If you did it on YouTube, I guess you'd be banned!

(just kidding; we all know that you can't possibly misinform people when you're agreeing with the party line!)

[1] https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

[srinivgp]

The paper you linked to says, in its summary section, "For the general public, evidence shows that physical distancing of more than 1 m is highly effective and that face masks are associated with protection, even in non-health-care settings, with either disposable surgical masks or reusable 12–16-layer cotton ones, although much of this evidence was on mask use within households and among contacts of cases."

But I assume you mean that the meta analysis didn't claim masks were useless, those three underlying papers did? I'm not sure what those three were, though, maybe I missed it. I found all the papers used but there were like a dozen in the non-health-care setting.

[timr]

That is their interpretation of the meta-analysis, yes ("summary section" == "discussion section"). That is not a statement of fact, but of the authors' opinions about the facts reported. The data stands on its own -- though in this case, since it's a meta-analysis with fancypants statistical re-weighting of the data, the line between "data" and "analysis" is decidedly blurred.

> But I assume you mean that the meta analysis didn't claim masks were useless, those three underlying papers did? I'm not sure what those three were, though, maybe I missed it. I found all the papers used but there were like a dozen in the non-health-care setting.

The data they have presented, aggregating ~all of the prior research literature on masks, shows a weak effect, at best. Only by mixing data from different settings (mostly hospitals) and different types of masks (from cloth to respirators) and re-weighting the conclusions do they arrive at this claim of even weak effectiveness.

Do masks work? Based on the literature, the only honest answer is "maybe they have a small effect, but the evidence isn't very good."

Compare this to what you see repeated in the media and by "experts". The truth is...most of these people haven't read the papers, and are just repeating what they've heard.

[kgarten]

Not improved?? I just checked nature...

https://www.nature.com/articles/s41591-020-0843-2 https://www.nature.com/articles/d41586-020-02801-8 https://www.nature.com/articles/s41467-021-24115-7

Seems pretty clear to me.

[timr]

The Leung et. al. paper (first link) should never have passed editorial review. Look at figure 1: the only significant result in the entire paper (1a, panel 3) is based on four data points. I don't know if this is p-hacking, per se, but it's not a robust result. And not that I give the paper a lot of credence, but it's worth nothing that the overall trend across all pathogens is that masks are ineffective against aerosols.

Link two is a news article and contributes no data.

Link three is a survey of people self-reporting a bunch of different things, where they've thrown out 32% of the data for non-response, selected the ones who did respond (bias!) and used that to make claims about face masks. Moreover, their data shows that as people wear face-masks more often, their chance of getting Covid goes up! This paper has so many confounders and potential sources of bias that it simply cannot be taken seriously.

When I said that the research literature on masks over 2020 hasn't gotten any better, these kinds of papers are exactly what I meant. They're terrible, they're littered with methodological and data analysis flaws, and provide no useful information to the debate. If these "seem clear to you", you don't understand what you're reading and lack the ability to assess research literature.

Sadly, top-tier journals publish a lot of garbage, particularly when that garbage is topical and will get press. You cannot use "Nature paper" as a badge of quality. You still have to read and understand the paper.

[kgarten]

For me that these papers get accepted is rather a sign that scientific consensus is on the side of masks work.

Usually, it takes 2 -5 years to get a nature paper ready (at least for the labs I know). Seeing also the pre-prints that were in the article that you dismissed as "news article." and others it seems a strong indication that most virologists and epidemiologists think masks work.

They might be wrong, yet I haven't heard any convincing theory or model on why that should be the case.

[timr]

> For me that these papers get accepted is rather a sign that scientific consensus is on the side of masks work.

Well that's a great way to confirm your biases. The "scientific consensus" was that the earth was the center of the universe, that infection was transmitted by miasma, that plate tectonics were a crackpot theory...I could go on.

Science is the history of well-controlled experiment overturning consensus thinking.

In any case, editorial review is a human process, and like all human processes, has ample sources of error. In this case, a big source of error is that the major scientific journals have spent the better part of 2020 falling all over themselves to publish garbage about Covid that gets press hits.

> Usually, it takes 2 -5 years to get a nature paper ready (at least for the labs I know).

This obviously isn't true in this case. The pandemic hasn't been around for that long!

Also, no, it doesn't take 2-5 years to put together an editorial. Even in normal times.

[kgarten]

> The "scientific consensus" was that the earth was the center of the universe.

Yes, and then somebody found a better model (that's also still wrong) yet explained more and we used it. So my question, what's your better model you base your assumptions on? Any scientific paper is wrong, you can find problems with any of them. Just, critique is easy and often doesn't lead anywhere.

my point: The scientific consensus right now is wearing masks help. This is supported by physics (particle simulations), medicine (respiratory disease and their transmission .. and a lot of other fields.

You say there's little data ... come on than make this > well-controlled experiment overturning consensus thinking

you can be famous!

https://www.japantimes.co.jp/news/2020/10/22/national/scienc...

Check the video, people are trying what would be an experimental setup you would accept? That is also ethically OK.

We have both controlled experiments that have reduced validity in the real world because of the artificial conditions and we have some more messy real world evidence. Seems OK to me.

The people I see on the other side don't offer an alternative model. Also a lot of the criticism comes from people who don't seem to have virology /immunology etc background.

> Usually, it takes 2 -5 years to get a nature paper ready (at least for the labs I know).

Yes, my point was these papers are rushed. It can be bias, it can be also that reviewers have their expertise that tells them the paper fits the evidence.

Change happens over models/explanations. I don't see any new ones from the "Masks don't work" folks. Just criticism (that's easy ... I'm happy to point out all the flaws in any paper you present me. If you want to kill a paper in peer review it's super easy ...)

For policy decisions shouldn't you use the current scientific consesus,however flawed it is? Is there a better solution? Otherwise you are just relying on your gut feeling. Good luck.

[kgarten]

forgot: here's the paper (it's just mentioned in Japanese in the video) https://journals.asm.org/doi/10.1128/mSphere.00637-20

your controlled experiment with Sars-COV-2 particles :)

[kgarten]

in terms of physics I see a good reason to wear a mask. If COVID did not invent a sneaky way to go around that

Article 2 has a whole lot of pre-prints with data in the citations ... :) Here's a follow up (also with a lot of paper citations : https://www.nature.com/articles/d41586-021-01394-0

Talking with friends who are virologists, they all seem to agree masks help.

What's wrong with the articles the nature commentary are based on And articles like that: https://journals.plos.org/plosone/article?id=10.1371/journal...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883189/#__ffn_...

[timr]

> Article 2 has a whole lot of pre-prints with data in the citations

This is yet another news article, written by a journalist (Lynne Peeples, who wrote the other Nature news article you've shared upthread) who is mostly re-hashing her previous article. Did you read it or follow the citations? This is an excellent example of hearsay: if you don't take the time to read the citations in detail, you won't realize what you're missing.

Most of the citations here are same citations in the previous Nature news article. Only citations 4-8 deal with the question of masks' impact on transmission (the remainder are for other questions, like whether vaccinated people can be infected). Of the papers in citations 4-8, two are new. Both are based on mathematical models using self-reported survey data and/or state-level case data. I don't know how good these papers are, but all studies of this form are low-quality medical evidence.

Unfortunately, bad journalists can re-hash the same crappy studies faster than skilled people can debunk their work.

> Talking with friends who are virologists, they all seem to agree masks help.

That's meaningless. You can find a sample of scientists to support pretty much anything.

> What's wrong with... https://journals.plos.org/plosone/article?id=10.1371/journal...

So many things. The paper uses survey responses (= bad data), and tries to correlate it with state-level infection curves (= blurry data), and only does it for a month-by-month difference for every month between April and September 2020, when cases were falling across all of north america. It sets arbitrary thresholds for "high cases" and "high mask wearing". It doesn't control for confounding factors, like other policies the states in question might have enacted.

This is a terrible paper. I cannot believe PLOS One published this. It is embarrassing.

> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883189/#__ffn_...

This is not a paper, it's a review. It presents no data. It summarizes the authors' opinions on other papers.

[kgarten]

So I don't know what you are arguing: We have a lot of evidence on the effectiveness of masks in relationship to preventing droplet infection.

We don't have so much about COVID 19. On the community level it looks promising for me, the papers are flawed but coming out.

What I am missing ... where is the other side of the coin. All models are wrong but some are useful. The particle simulations are wrong, but pretty useful (and I don't see why COVID should behave differently). What model do you base your assumption that masks don't work? Is there research that supports your claims? All science is bad science :) Some is useful.

> survey responses (= bad data)? So any research based on survey responses is bad? It's a standard method in policy research. What data would you use to show the community effect of mask wearing?

I'm usually listening critically to experts in a field (not to dentists or surgeons), it seems people who claim masks don't work are not virologists and have not worked with the virus (COVID19): https://en.wikipedia.org/wiki/Christian_Drosten https://en.wikipedia.org/wiki/Sandra_Ciesek

Both strong in the pro mask camp. Are there virologists working on COVID 19 (in the lab) that are on your side of the argument?

[kgarten]

Anecdotal, how do you explain the non existing flue season (last autumn ) and the low incidences in Japan? We got higher rates during the Olympic.

I live in Tokyo, Japan and visit US/Europe often. The only significant difference I see is the willingness to wear masks. And there's way less space here (packed subways etc.)

[timr]

Well, any rational conversation about Japan has to start with the observation that cases are at an all-time high right now:

https://www.asahi.com/topics/word/%E3%82%B3%E3%83%AD%E3%83%8...

I don't think changing rates of masking can explain that change.

> Anecdotal, how do you explain the non existing flue season (last autumn ) and the low incidences in Japan? We got higher rates during the Olympic.

I haven't seen any data on flu during the olympics, so I can't comment on that. Covid cases, of course, were shooting up long before the first athletes even arrived in Japan (see above).

To answer your question, nobody knows why flu "disappeared" during the last year. My hypothesis is a combination of two things:

1) it didn't disappear, it just spread less due to to the dramatic reduction in international travel (plus maybe closure of schools).

2) we stopped testing for flu at rates necessary to detect it. Our prior surveillance system for influenza was pretty limited, and most of it switched to Covid in 2020.

In general, I think people fixate on masks far too much, because they're visible. Even in Japan, what qualifies as a mask would make Americans in the "mask compliant" cities laugh out loud. I routinely see people wearing these on Instagram and on television:

https://www.superdelivery.com/product_image/812/8/8128738_10...

[kgarten]

... the increase in incidences are coinciding with early travel and reducing the state of emergency related to the olympic. I work at a place that housed one of the teams, and the incidence increased around 1-2 weeks after some people arrived.

NHK made a lot of efforts like the one bellow: https://www3.nhk.or.jp/nhkworld/en/news/backstories/1247/

Check the video,I would say masks help. It's basic physics ...

it's similar to the seat belt and car discussion. It's debatable how much they help (and they might have increased the number of accidents initially), yet they help. Statistics is hard.

[timr]

> Check the video,I would say masks help. It's basic physics

Masks leak. Airflow seeks the path of least resistance. Also basic physics. People are not mannequins in a fume hood with scrap of cloth glued to their slobberhole.

I don't think anyone is disputing the idea that if you could somehow hermetically seal off everyone's face holes, you'd stop the spread of a respiratory virus. But we can't, and we don't, so the question becomes: in the real world (i.e. not a mannequin in a lab), does it make a difference?

All of the real-world evidence on the question is mixed, at best.

[kgarten]

what is the risk of wearing a mask? that you look silly?

the real world evidence is mixed, yes.

People are not mannequins, people die. If a simple action of mine, that might make me look silly, might save some lives (might, I don't know, yet from annexdotes countries that had no problem with wearing masks and other measures faired better) I will do what these countries did (and also wear a mask). It's rational compassion for me.

You might say, I don't care (and science might prove you right or wrong after a long while), yet consider the potential cost if you are proven wrong ... Looking silly versus potentially killing people ... The evidence is not in, and it depends on what you value more ;)

It's your own choice. For me I decided to wear a mask in public, do social distancing and get vaccinated. I think these are reasonable things to ask from people. You don't seem to think that.

[timr]

> what is the risk of wearing a mask? that you look silly?

Fortunately, "lack of silliness" is not the standard of evidence for a medical intervention.

There are a great many things that we might impose on others that might have some impact. There are, in fact, an infinite number of these things.

Your desire to do these things "just in case" does not justify their imposition on other people. But more importantly: we've had a long time to study this intervention now. Perhaps it's time to gather some actual evidence that it works?

After all, it's not just the question of whether or not I want to do it -- it's the question of whether or not huge number of people are convinced that they're protecting themselves, and somehow behaving differently out of a misguided sense of protection. That matters quite a bit.

> It's rational compassion for me.

No, without evidence, it's just a guess.

[kgarten]

anything that interfere with droplet dispersion is better than nothing ... no? https://www.youtube.com/watch?v=pwOwMsCc6NA

https://www.youtube.com/watch?v=GAvO_QdO9eM

Seems basic to me ... If the droplets from me don't reach to the first person in the cinema I cannot infect them.

[belorn]

> If the droplets from me don't reach to the first person in the cinema I cannot infect them.

It would be nice if that was true. In a small study here in Sweden they tested for covid particles in the AC system, and found particles in every single place they tested. This in a major hospital where everyone are wearing masks, and where the AC is located in the ceiling. The finding was not what the researcher was expecting, especially not in the AC system located on the roof.

How much interference a mask has is determined by the leak rating, but for most surgical masks there are no protection for the finer droplets in coughs and sneezes.

In a similar style, people though initially that bath houses and saunas would be safe against covid because the large droplets in the humid air would drop quickly to the ground. Later it was generally agreed here that the conclusion was incorrect and all public bath houses and saunas closed. Like with masks, humid air might be better than nothing but you really do not want to be near a person who are sick unless you got yourself an air filter and face shield.

[kgarten]

Yes, that's the point masks are better than nothing. They might reduce the likelihood (without much of a negative impact). That's why we should wear them.

A vaccination also just reduces the likelihood you get covid. People can still get it and still spread it, even if they are vaccinated. It just reduces the likelihood and masks might do that as well ...

[belorn]

Yes, through masks don't reduce the likelihood of infection in the same way like vaccinations. The vaccination significant reduce infection rate for the person who takes it. Any secondary effect on other people is the result of the vaccinated person not being sick. Mask on other hand might in a limited way reduce spread if the person who wear it is sick. Masks without intake filters has zero effect on the person who wears the mask.

Vaccinations also have requirements with generally 90%+ protection, while masks has anything from 0 to 90% effectiveness in filtering breath emissions. As a effective measure against covid, vaccinations are a much more effective and powerful tool.

After two years and in my experience, you can't have large gatherings and expect a low risks. Neither vaccines nor mask nor the combination of both can produce enough of an defense. 2m distancing, washing hands, and keeping human gatherings inside to an absolute minimum is the only way, and then follow up with mass vaccinations. I don't think given current scientific knowledge that one can cheat that process.

[timr]

Science is the history of people debunking ideas that "seem basic" to other people.

Those are called "hypotheses", and they're great. The next step is to find evidence that proves the hypothesis...and that's where we're stuck here.

[kgarten]

Science is the history of people seeing something basic and getting told by others that it's not true ... E.g. the earth is round. Yet, You can never prove a hypothesis just present more and more evidence.

My point: it does not hurt me to wear a mask and it might help people, so I will do it. It seems also that scientists who know more about this than me, support this idea. They might be wrong, yet even if they are the negative consequences are so low (I wore a mask for a couple of days ... ) that for me it's worth it.

When I hear Rand Paul, I hear the smuggness of "I know masks don't work" and sorry but we don't know that ... Saying this right now, is showing me that he does not understand science (we don't know, they might help) and that he does not have any compassion.

Fauci seems to have the better track record (seeing how he dealt with AIDS).

[nickthemagicman]

Not driving a car might help people also.

Not leaving your house also might help people.

If it 'might help people' why not either of those options?

[nickthemagicman]

Masks work in healthcare settings due to proper mask usage and training.

The problem is at the community level.

The current world mask usage is: "Wear a filth rag on your face until the waiter brings the breadsticks".

This could actually be doing more harm than good.

[nickthemagicman]

Thanks for posting. No one on the pro-mask side reads scientific papers.

They're fascists and want to crush their opposition through controlling the narrative instead of actual science.