8 ms·

On the contrary, there's actually very little evidence that masks are effective for the general public. Particularly for cloth masks, the evidence is essentiall

by timr 6y ago

On the contrary, there's actually very little evidence that masks are effective for the general public. Particularly for cloth masks, the evidence is essentially non-existent. You're citing an article by Jeremy Howard, who is quoted in the OP, and whose opinion is directly rebutted. Michael Osterholm of CIDRAP has written a rather scathing summary of the data for cloth masks, and the political and social machinations that have gotten us where we are. He calls out Jeremy Howard as a particularly vocal spreader of scientific misinformation on the topic: https://www.cidrap.umn.edu/covid-19/podcasts-webinars/special-ep-masks https://www.cidrap.umn.edu/covid-19/podcasts-webinars/specia... (edit: how can you possibly downvote a link to a factual source that is cited in the article? Consider your bias.)

cmiles74 6y ago
In my opinion, it's unreasonable to expect that there would be studies on the effects of cloth masks. Up until the quarantine began the reasonable assumption was that if you needed a mask you wore the one appropriate to your task. I don't think cloth masks were in widespread use until these masks became scarce. Maybe some studies are happening now. Even so, it probably makes more sense to encourage people to purchase more reliable masks.
- timr 6y ago
  "In my opinion, it's unreasonable to expect that there would be studies on the effects of cloth masks." That's fine, but there are lots of plausible interventions that have little/no evidence, and we don't mandate those by law. Why this one? For example, the Lancet study commissioned by the WHO found that eye protection is about as supported by the available literature as surgical masks. Why aren't we all required to wear goggles? I believe that "science" should not be used to mandate actions that have no scientific data backing them. "it probably makes more sense to encourage people to purchase more reliable masks." The issue there is still shortages. I don't buy surgical or n95 masks, because other people need them more than I do.
  - ceejayoz 6y ago
    > For example, the Lancet study commissioned by the WHO found that eye protection is about as supported by the available literature as surgical masks. Why aren't we all required to wear goggles? Because masks are being recommended to work on outgoing virus. Unless you've evidence respiratory viruses spread significantly via jets of air emitted via your eyeballs, this is a weird argument.
    - timr 6y ago
      "because masks are being recommended to work on outgoing virus. Unless you've evidence respiratory viruses spread significantly via jets of air emitted via your eyeballs, this is a weird argument." If you read the Lancet paper, you'll find that they pooled papers for source control and PPE together to arrive at their conclusions. In fact, most of the papers they used in that meta-analysis were for surgical masks used as PPE (personal protective equipment) in a medical setting. In other words, the advocates for masking are doing the same thing that you're saying is weird. If you try to break the analysis down according to specific lines of evidence (i.e. source control for the public), you quickly find that there's not enough data to draw any conclusion. On the other hand, the argument in favor of this kind of pooling is straightforward: if your end goal is to reduce transmission of a virus, and you find that goggles are highly effective at preventing infection, then it doesn't matter very much. Tell everyone to wear goggles instead, and forget about the masks. Transmission will still be reduced.
      - ceejayoz 6y ago
        Medical settings are concerned largely with PPE that protects the staff, and a number of healthcare procedures are aerosol-generating. Mask wearing for COVID is targeted at reducing likelihood of spreading to someone else. > If you try to break the analysis down according to specific lines of evidence (i.e. source control for the public), you quickly find that there's not enough data to draw any conclusion. We're going to get a lot of data soon, but for the time being, it's probably best to err on the side of "something that stops droplets probably helps stop a disease spread by droplets".
- clarus 6y ago
  Before the spread of disposable masks (a few dozens of years back), the masks were made of cloth. Look at the pictures from the 1918 fever for example. I guess studies were made, it would be interesting to know what people thought.
- thoraway3030 6y ago
  This brings up an interesting question: why are people around the world still being encouraged/mandated to use cloth masks (whatever their efficacy)? Surely manufacturers and supply chains for conventional masks have caught up with the demand by now?
- DanBC 6y ago
  "Masks" covers various types of respirator (such as N95 or FFP3), and fluid-resistant surgical mask, and surgical masks that are not fluid resistant. We have lots of evidence for all of these, and most of that evidence doesn't show any benefit for surgical masks that are not fluid resistant.
nickthemagicman 6y ago
I fully support your critical thinking about masks. There's conclusive evidence that masks help on a micro level by stopping droplets. It's possible that masks also increase aggregate infection rate by requiring a population uneducated in mask usage to apply a potential plague vector directly to their faces. It will be shocking if science does come back in the future and indicates that mask usage reduces the chance of spreading covid BUT INCREASES ones chance of contracting it. Mask usage is important and many people don't know how to use a mask properly. If someone puts a cloth mask on backwards they're inhaling a virus that stays on surfaces for days. Masks may also increase the chance of infection by causing people to put their hands near their face more often to adjust or don the mask. Even in the most recent World Health Organization report: "At the present time, the widespread use of masks by healthy people in the community setting is not yet supported by high quality or direct scientific evidence and there are potential benefits and harms to consider " Additionally Sweden had no mask laws and its infection rate has stabilized while place with mask laws like Cali and Washington have skyrocketing rates of infection. Masks have become a religious war and most people accept it without question and have never looked a single shred of research from legitimate sources that aren't news media based. I personally think it gives people the feeling of power over a powerless situation. I just hate to see laws forcing people to do something backed by weak science and I hope this isn't like Thalidomide or Lead paint where experts validated something based on weak science that turned out to be wrong.
- ceejayoz 6y ago
  > It's possible that masks also increase aggregate infection rate by requiring a population uneducated in mask usage to apply a potential plague vector directly to their faces. If there's SARS-CoV-2 on your mask, there'd be SARS-CoV-2 on your unmasked face if you weren't wearing one. Right?
  - nickthemagicman 6y ago
    You should check out how skin works sometime, it's pretty interesting. Believe it or not it's pretty dissimilar to paper or fabric. https://health.howstuffworks.com/skin-care/information/anatomy/shed-skin-cells.htm https://health.howstuffworks.com/skin-care/information/anato...
woodandsteel 6y ago
So what are you saying public policy should be? You know, there are basically two groups of countries in the world today. In one group there have been a strong set of policies to fight the virus, and it includes face masks, and in this group the virus has been beaten back. In the other countries, including the US, things have been much more lax, including lots of people not wearing face masks, and the virus has exploded. So are you saying the correct public policy should be strong measures on things like social distancing and contact tracing, but people should be free to not wear face masks? Why take a chance with that when we know the set of policies that includes face masks works? Or perhaps you are the one of the people, like Trump, Bolsonaro and others, who is for lax policies all around.
- nickthemagicman 6y ago
  Where's your reference for """In one group there have been a strong set of policies to fight the virus, and it includes face masks, and in this group the virus has been beaten back.""" California and Washington both have mask laws and their infection rates have skyrocketed.
  - woodandsteel 6y ago
    I live in California, and the mask rules at the state level were not dictated, only recommended, and in most locations where they were law they were not rigorously enforced. And then Gov Newsome relaxed social distancing, and the infection rate shot up. But tell me, what do you think the policies should be, for masks and everything else?
    - nickthemagicman 6y ago
      Just asking for your reference on this statement: """In one group there have been a strong set of policies to fight the virus, and it includes face masks, and in this group the virus has been beaten back.""" Because you're making it sound much more conclusive than what I've been seeing.
      - 6y ago
jph00 6y ago
Osterholm's claims are not supported by the evidence. He claims to respect aerosol scientists, but doesn't have any on his team and none have been involved in his team's work on this issue. He claims that people that are experts in modeling have not modeled correctly, despite having no familiarity with modeling. On the other hand, our paper includes one of the world's top aerosol scientists, along with top epidemiologists, biostatisticians, and other experts. https://www.preprints.org/manuscript/202004.0203/v2 https://www.preprints.org/manuscript/202004.0203/v2 The rubbish spouted by CIDRAP about masks is very obviously flawed, as you can see for example here: https://www.fast.ai/2020/04/20/skeptics-masks/#what-about-the-article-masks-for-all-for-covid-19-not-based-on-sound-data https://www.fast.ai/2020/04/20/skeptics-masks/#what-about-th... Osterholm has never written any paper about community mask wearing. He is not an informed authority on this issue. The efficacy of masks has now been very clearly shown in multiple studies, e.g: https://gh.bmj.com/content/5/5/e002794 https://gh.bmj.com/content/5/5/e002794 https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(20)30133-X/fulltext https://www.thelancet.com/journals/lanpub/article/PIIS2468-2... https://www.healthaffairs.org/doi/10.1377/hlthaff.2020.00818 https://www.healthaffairs.org/doi/10.1377/hlthaff.2020.00818
- timr 6y ago
  "Osterholm has never written any paper about community mask wearing. He is not an informed authority on this issue" And neither are you. Your "paper" on the subject is a joke. I've read it, and I've read the source literature you cite. It is a series of sloppy misinterpretations and mis-representations of the other papers, coupled with the results of running an ad hoc epidemiological model with questionable parameters. It is a quora post, written up like a paper, and pushed to a pre-print server. You cite papers that are rated by Cochrane (and others) as low-quality, as if they are reliable evidence. You dismiss papers that do not support your conclusions for "lack of evidence", but deflect similar criticisms of your own conclusions with "absence of evidence is not evidence of absence". Quite simply: your analysis wouldn't pass muster at even a third-rate journal, and Osterholm has rightly called you out on it. It's especially ironic that you say that Osterholm is not an "informed authority" -- he leads one of the country's leading research institutes on infectious disease, has a long history in epidemiology and public health, and spends the better part of an hour-long podcast specifically describing his experience and outlining areas where he has no specific expertise. Say what you want about the man, but he is rigorously honest about his experience. Yet I regularly see you cited as a "mask expert". Where did you do your research, again? Was it when you were getting a philosophy degree, or when you were at Fastmail? Maybe Kaggle has a mask competition? As for the papers you've cited here: the first link you cite can't separate the effects of social distancing, gloves, masks, and other interventions, and finds mainly that people who take precautions against infection have better outcomes than those who don't. When they actually try to break out masks, specifically, they find that they don't have any effect after illness onset, which should make you doubt legitimacy of the results. The second link provides no evidence for masks. It is a modeling study. The third link has the same problem as the first, but worse: it can't possibly separate the effect of masks from everything else that was happening in the examined states at the same time. There is no control.

by timr 6y ago

cmiles74 6y ago

In my opinion, it's unreasonable to expect that there would be studies on the effects of cloth masks. Up until the quarantine began the reasonable assumption was that if you needed a mask you wore the one appropriate to your task. I don't think cloth masks were in widespread use until these masks became scarce. Maybe some studies are happening now. Even so, it probably makes more sense to encourage people to purchase more reliable masks.

timr 6y ago
"In my opinion, it's unreasonable to expect that there would be studies on the effects of cloth masks." That's fine, but there are lots of plausible interventions that have little/no evidence, and we don't mandate those by law. Why this one? For example, the Lancet study commissioned by the WHO found that eye protection is about as supported by the available literature as surgical masks. Why aren't we all required to wear goggles? I believe that "science" should not be used to mandate actions that have no scientific data backing them. "it probably makes more sense to encourage people to purchase more reliable masks." The issue there is still shortages. I don't buy surgical or n95 masks, because other people need them more than I do.
- ceejayoz 6y ago
  > For example, the Lancet study commissioned by the WHO found that eye protection is about as supported by the available literature as surgical masks. Why aren't we all required to wear goggles? Because masks are being recommended to work on outgoing virus. Unless you've evidence respiratory viruses spread significantly via jets of air emitted via your eyeballs, this is a weird argument.
  - timr 6y ago
    "because masks are being recommended to work on outgoing virus. Unless you've evidence respiratory viruses spread significantly via jets of air emitted via your eyeballs, this is a weird argument." If you read the Lancet paper, you'll find that they pooled papers for source control and PPE together to arrive at their conclusions. In fact, most of the papers they used in that meta-analysis were for surgical masks used as PPE (personal protective equipment) in a medical setting. In other words, the advocates for masking are doing the same thing that you're saying is weird. If you try to break the analysis down according to specific lines of evidence (i.e. source control for the public), you quickly find that there's not enough data to draw any conclusion. On the other hand, the argument in favor of this kind of pooling is straightforward: if your end goal is to reduce transmission of a virus, and you find that goggles are highly effective at preventing infection, then it doesn't matter very much. Tell everyone to wear goggles instead, and forget about the masks. Transmission will still be reduced.
    - ceejayoz 6y ago
      Medical settings are concerned largely with PPE that protects the staff, and a number of healthcare procedures are aerosol-generating. Mask wearing for COVID is targeted at reducing likelihood of spreading to someone else. > If you try to break the analysis down according to specific lines of evidence (i.e. source control for the public), you quickly find that there's not enough data to draw any conclusion. We're going to get a lot of data soon, but for the time being, it's probably best to err on the side of "something that stops droplets probably helps stop a disease spread by droplets".
clarus 6y ago
Before the spread of disposable masks (a few dozens of years back), the masks were made of cloth. Look at the pictures from the 1918 fever for example. I guess studies were made, it would be interesting to know what people thought.
thoraway3030 6y ago
This brings up an interesting question: why are people around the world still being encouraged/mandated to use cloth masks (whatever their efficacy)? Surely manufacturers and supply chains for conventional masks have caught up with the demand by now?
DanBC 6y ago
"Masks" covers various types of respirator (such as N95 or FFP3), and fluid-resistant surgical mask, and surgical masks that are not fluid resistant. We have lots of evidence for all of these, and most of that evidence doesn't show any benefit for surgical masks that are not fluid resistant.

nickthemagicman 6y ago

I fully support your critical thinking about masks. There's conclusive evidence that masks help on a micro level by stopping droplets. It's possible that masks also increase aggregate infection rate by requiring a population uneducated in mask usage to apply a potential plague vector directly to their faces. It will be shocking if science does come back in the future and indicates that mask usage reduces the chance of spreading covid BUT INCREASES ones chance of contracting it. Mask usage is important and many people don't know how to use a mask properly. If someone puts a cloth mask on backwards they're inhaling a virus that stays on surfaces for days. Masks may also increase the chance of infection by causing people to put their hands near their face more often to adjust or don the mask. Even in the most recent World Health Organization report: "At the present time, the widespread use of masks by healthy people in the community setting is not yet supported by high quality or direct scientific evidence and there are potential benefits and harms to consider " Additionally Sweden had no mask laws and its infection rate has stabilized while place with mask laws like Cali and Washington have skyrocketing rates of infection. Masks have become a religious war and most people accept it without question and have never looked a single shred of research from legitimate sources that aren't news media based. I personally think it gives people the feeling of power over a powerless situation. I just hate to see laws forcing people to do something backed by weak science and I hope this isn't like Thalidomide or Lead paint where experts validated something based on weak science that turned out to be wrong.

ceejayoz 6y ago
> It's possible that masks also increase aggregate infection rate by requiring a population uneducated in mask usage to apply a potential plague vector directly to their faces. If there's SARS-CoV-2 on your mask, there'd be SARS-CoV-2 on your unmasked face if you weren't wearing one. Right?
- nickthemagicman 6y ago
  You should check out how skin works sometime, it's pretty interesting. Believe it or not it's pretty dissimilar to paper or fabric. https://health.howstuffworks.com/skin-care/information/anatomy/shed-skin-cells.htm https://health.howstuffworks.com/skin-care/information/anato...

woodandsteel 6y ago

So what are you saying public policy should be? You know, there are basically two groups of countries in the world today. In one group there have been a strong set of policies to fight the virus, and it includes face masks, and in this group the virus has been beaten back. In the other countries, including the US, things have been much more lax, including lots of people not wearing face masks, and the virus has exploded. So are you saying the correct public policy should be strong measures on things like social distancing and contact tracing, but people should be free to not wear face masks? Why take a chance with that when we know the set of policies that includes face masks works? Or perhaps you are the one of the people, like Trump, Bolsonaro and others, who is for lax policies all around.

nickthemagicman 6y ago
Where's your reference for """In one group there have been a strong set of policies to fight the virus, and it includes face masks, and in this group the virus has been beaten back.""" California and Washington both have mask laws and their infection rates have skyrocketed.
- woodandsteel 6y ago
  I live in California, and the mask rules at the state level were not dictated, only recommended, and in most locations where they were law they were not rigorously enforced. And then Gov Newsome relaxed social distancing, and the infection rate shot up. But tell me, what do you think the policies should be, for masks and everything else?
  - nickthemagicman 6y ago
    Just asking for your reference on this statement: """In one group there have been a strong set of policies to fight the virus, and it includes face masks, and in this group the virus has been beaten back.""" Because you're making it sound much more conclusive than what I've been seeing.
    - 6y ago

jph00 6y ago

Osterholm's claims are not supported by the evidence. He claims to respect aerosol scientists, but doesn't have any on his team and none have been involved in his team's work on this issue. He claims that people that are experts in modeling have not modeled correctly, despite having no familiarity with modeling. On the other hand, our paper includes one of the world's top aerosol scientists, along with top epidemiologists, biostatisticians, and other experts. https://www.preprints.org/manuscript/202004.0203/v2 https://www.preprints.org/manuscript/202004.0203/v2 The rubbish spouted by CIDRAP about masks is very obviously flawed, as you can see for example here: https://www.fast.ai/2020/04/20/skeptics-masks/#what-about-the-article-masks-for-all-for-covid-19-not-based-on-sound-data https://www.fast.ai/2020/04/20/skeptics-masks/#what-about-th... Osterholm has never written any paper about community mask wearing. He is not an informed authority on this issue. The efficacy of masks has now been very clearly shown in multiple studies, e.g: https://gh.bmj.com/content/5/5/e002794 https://gh.bmj.com/content/5/5/e002794 https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(20)30133-X/fulltext https://www.thelancet.com/journals/lanpub/article/PIIS2468-2... https://www.healthaffairs.org/doi/10.1377/hlthaff.2020.00818 https://www.healthaffairs.org/doi/10.1377/hlthaff.2020.00818

timr 6y ago
"Osterholm has never written any paper about community mask wearing. He is not an informed authority on this issue" And neither are you. Your "paper" on the subject is a joke. I've read it, and I've read the source literature you cite. It is a series of sloppy misinterpretations and mis-representations of the other papers, coupled with the results of running an ad hoc epidemiological model with questionable parameters. It is a quora post, written up like a paper, and pushed to a pre-print server. You cite papers that are rated by Cochrane (and others) as low-quality, as if they are reliable evidence. You dismiss papers that do not support your conclusions for "lack of evidence", but deflect similar criticisms of your own conclusions with "absence of evidence is not evidence of absence". Quite simply: your analysis wouldn't pass muster at even a third-rate journal, and Osterholm has rightly called you out on it. It's especially ironic that you say that Osterholm is not an "informed authority" -- he leads one of the country's leading research institutes on infectious disease, has a long history in epidemiology and public health, and spends the better part of an hour-long podcast specifically describing his experience and outlining areas where he has no specific expertise. Say what you want about the man, but he is rigorously honest about his experience. Yet I regularly see you cited as a "mask expert". Where did you do your research, again? Was it when you were getting a philosophy degree, or when you were at Fastmail? Maybe Kaggle has a mask competition? As for the papers you've cited here: the first link you cite can't separate the effects of social distancing, gloves, masks, and other interventions, and finds mainly that people who take precautions against infection have better outcomes than those who don't. When they actually try to break out masks, specifically, they find that they don't have any effect after illness onset, which should make you doubt legitimacy of the results. The second link provides no evidence for masks. It is a modeling study. The third link has the same problem as the first, but worse: it can't possibly separate the effect of masks from everything else that was happening in the examined states at the same time. There is no control.