An evidence review of face masks against COVID-19

[BoyNextDoor]

https://www.pnas.org/content/118/4/e2014564118

Abstract
The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wearer protection, sociological considerations, and implementation considerations. A primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals. Reducing disease spread requires two things: limiting contacts of infected individuals via physical distancing and other measures and reducing the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. Given the current shortages of medical masks, we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory particles become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask wearing by infectious people (“source control”) with benefits at the population level, rather than only mask wearing by susceptible people, such as health care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

 

[BabyBoomer50s]

https://www.pnas.org/content/118/4/e2014564118

Abstract
The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wearer protection, sociological considerations, and implementation considerations. A primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals. Reducing disease spread requires two things: limiting contacts of infected individuals via physical distancing and other measures and reducing the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. Given the current shortages of medical masks, we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory particles become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask wearing by infectious people (“source control”) with benefits at the population level, rather than only mask wearing by susceptible people, such as health care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

“Therefore, we should not be surprised to find that there is no RCT for the impact of masks on community transmission of any respiratory infection in a pandemic.”

Good grief. There are at least 14 RCTs on this.

 

[Dribble]

All peer reviewed research says the same thing. Only Fascist traitors say they don't work

 

[BoyNextDoor]

“Therefore, we should not be surprised to find that there is no RCT for the impact of masks on community transmission of any respiratory infection in a pandemic.”

Good grief. There are at least 14 RCTs on this.

No RCT for Masks? No Problem
— Other forms of evidence are available to judge effectiveness of this and other interventions

But what constitutes evidence in this context? There has been an almost exclusive focus on evidence from experimental studies, specifically the randomized controlled trial (RCT), which is characterized as the "gold standard" of research, as it allows for the determination of causality. However, the reason such evidence is still lacking, should be obvious – the RCT is neither feasible nor appropriate for determining the effectiveness of mask-wearing in the community in protecting against COVID-19, and moreover, its use will be considered unethical in the context of a deadly pandemic. At the minimum, an RCT would require manipulation of the intervention, by way of the researcher randomly assigning some members of the community to wear a face mask and others not to, and ensuring that both community groups are similar, based on key background characteristics, in other words, controlling for potential confounding factors.

An RCT may be theoretically perfect, but it is certainly not realistic in the context of mask-wearing and the COVID-19 pandemic. What is more relevant, meaningful, and available, is evidence from the observational research spectrum, primarily natural experiments. A natural experiment is an observational study where an intervention such as mask-wearing was implemented by forces outside the researcher's control, such as a governmental mandate, and the outcome (level of COVID-19 infection) can be used to explore a specific research question, for example: Does mask-wearing in the community setting reduce the level of COVID-19 infection? The results can be evaluated for causal inference, using a common epidemiological model known as the Bradford-Hill criteria.

Appreciating and using evidence other than from "true" experiments (i.e., an RCT) can be difficult especially in the health professions where the research culture is driven primarily by the hypothetico-deductive reasoning model; a closed or circular system of logic which can limit discovery and innovation. There is an urgent need for greater intellectual flexibility and curiosity.

 

[Bud_Spencer]

All peer reviewed research says the same thing. Only Fascist traitors say they don't work

You mean like Biden's top epidemiologist?

 

[innocntplay]

While wearing your mask have you smelled someone else fart?

Guessing it passed through 2 layers of fabric before it passed through the mask....

How big is a fart molecule?

How big is the covid aerosol?

No RCT for Masks? No Problem
— Other forms of evidence are available to judge effectiveness of this and other interventions

But what constitutes evidence in this context? There has been an almost exclusive focus on evidence from experimental studies, specifically the randomized controlled trial (RCT), which is characterized as the "gold standard" of research, as it allows for the determination of causality. However, the reason such evidence is still lacking, should be obvious – the RCT is neither feasible nor appropriate for determining the effectiveness of mask-wearing in the community in protecting against COVID-19, and moreover, its use will be considered unethical in the context of a deadly pandemic. At the minimum, an RCT would require manipulation of the intervention, by way of the researcher randomly assigning some members of the community to wear a face mask and others not to, and ensuring that both community groups are similar, based on key background characteristics, in other words, controlling for potential confounding factors.

An RCT may be theoretically perfect, but it is certainly not realistic in the context of mask-wearing and the COVID-19 pandemic. What is more relevant, meaningful, and available, is evidence from the observational research spectrum, primarily natural experiments. A natural experiment is an observational study where an intervention such as mask-wearing was implemented by forces outside the researcher's control, such as a governmental mandate, and the outcome (level of COVID-19 infection) can be used to explore a specific research question, for example: Does mask-wearing in the community setting reduce the level of COVID-19 infection? The results can be evaluated for causal inference, using a common epidemiological model known as the Bradford-Hill criteria.

Appreciating and using evidence other than from "true" experiments (i.e., an RCT) can be difficult especially in the health professions where the research culture is driven primarily by the hypothetico-deductive reasoning model; a closed or circular system of logic which can limit discovery and innovation. There is an urgent need for greater intellectual flexibility and curiosity.

 

[BoyNextDoor]

You mean like Biden's top epidemiologist?

The often repeated lie ....

 

[Bud_Spencer]

The often repeated lie ....

He was just on the teevee saying ho ineffective masks are.

 

[ll74]

While wearing your mask have you smelled someone else fart?

Guessing it passed through 2 layers of fabric before it passed through the mask....

How big is a fart molecule?

How big is the covid aerosol?

Covid virus does not get expressed as a singular molecule. The virus attaches itself to other virus molecules as well as mucus.

I.e. the molecule size argument is bullshit

 

[BoyNextDoor]

While wearing your mask have you smelled someone else fart?

Guessing it passed through 2 layers of fabric before it passed through the mask....

How big is a fart molecule?

How big is the covid aerosol?

Aerosol to carry covid is 4.7 microns. Fart gasses, O2 and CO2 are all around 0.00033 microns wide.

So you can safely breath in O2, exhale CO2 and smell farts while mask wearing and keep inside the mask all your covid laden 4.7 micron particles and not inhale other's 4.7 micron and larger particles laden with the virus (the coronavirus itself is about 0.1 microns wide).

 

[BoyNextDoor]

He was just on the teevee saying ho ineffective masks are.

Michael Osterholm?

 

[butters]

https://imgur.com/gallery/hyek2jv

 

[DeluxAuto]

 

[BoyNextDoor]

https://imgur.com/gallery/hyek2jv

Good for me, not for thee

 

[innocntplay]

Aerosol to carry covid is 4.7 microns. Fart gasses, O2 and CO2 are all around 0.00033 microns wide.

So you can safely breath in O2, exhale CO2 and smell farts while mask wearing and keep inside the mask all your covid laden 4.7 micron particles and not inhale other's 4.7 micron and larger particles laden with the virus (the coronavirus itself is about 0.1 microns wide).

Not according to Whiteface. He says there is no reason to wear a mask at all. It cannot travel like that.

And believe me he knows everything!

 

[ll74]

Not according to Whiteface. He says there is no reason to wear a mask at all. It cannot travel like that.

And believe me he knows everything!

Whiteface..lol....how endearing. But yah...that's not what I said.

 

[WillJ8787]

https://www.pnas.org/content/118/4/e2014564118

Abstract
The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wearer protection, sociological considerations, and implementation considerations. A primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals. Reducing disease spread requires two things: limiting contacts of infected individuals via physical distancing and other measures and reducing the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. Given the current shortages of medical masks, we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory particles become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask wearing by infectious people (“source control”) with benefits at the population level, rather than only mask wearing by susceptible people, such as health care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.

Thank you for providing an intelligent bit of info on mask efficacy and a science based source where they do research and publish the findings.

Masks do help!

 

[BabyBoomer50s]

Randomized controlled trials are the gold standard. Hard to ignore what they show, but feel free to ignore them if you wish. Keep wearing your mask. They are terrific for hiding your zits. They might even create more zits.

 

[Bud_Spencer]

Michael Osterholm?

yep, him.

 

[WillJ8787]

All peer reviewed research says the same thing. Only Fascist traitors say they don't work

...and Pudpuller Is a self described EE... Chuckles...just like Corncobbuphisass is a Biologist... chuckles!

 

[ll74]

Randomized controlled trials are the gold standard. Hard to ignore what they show, but feel free to ignore them if you wish. Keep wearing your mask. They are terrific for hiding your zits. They might even create more zits.

I'm sure if you ask your doctor, they'd agree. :/

 

[phrodeau]

Arnold Schwarzeneggar says, “Screw your freedom. You’re a schmuck for not wearing a mask.”

https://www.sfgate.com/california-p...gger-video-viral-mask-rant-COVID-16382436.php

 

[pecksniff]

You mean like Biden's top epidemiologist?

That would be Dr. Fauci, and he says masks work.

 

[pecksniff]

Arnold Schwarzeneggar says, “Screw your freedom. You’re a schmuck for not wearing a mask.”

https://www.sfgate.com/california-p...gger-video-viral-mask-rant-COVID-16382436.php

Well, of course, Schwarzenegger is No True Republican. (If he were, he could not have been governor of California.)