"If your underwear won't keep a fart in, why do you think a mask will keep germs out?". (Great question from a vaccinated basketball dad yesterday at practice.).

While RCTs are great, you can't use them in many instances in which it's unethical to withhold the treatment you're studying or instances in which participant knowledge that they have received the treatment (eg, wearing a mask) will affect how they behave. So in these situations you have to use other experimental methodologies (eg, propensity score matching).

Can't we look at the RCTs conducted for masks and other respiratory illnesses? There are several that have been done in Asia pre-covid that did not show that masks improve the situation.

Masks will keep individuals and those around them safer.

As public policy they failed to make any difference with the original Covid virus. How well the public policy of mask wearing will work for the new variants is unknown at this point. The fact that vaccinated people are most likely to masks up makes it a hard thing to study now.

SamHou said:

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While RCTs are great, you can't use them in many instances in which it's unethical to withhold the treatment you're studying or instances in which participant knowledge that they have received the treatment (eg, wearing a mask) will affect how they behave. So in these situations you have to use other experimental methodologies (eg, propensity score matching).

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Hate to break it to you, but this is exactly how they developed vaccines for covid-19. I highly recommend listening to the Radiolab podcast called "The Great Vaccinator." They dig into how vaccines are developed and interview some people that signed up for RTCs to be injected with covid-19.

https://www.wnycstudios.org/podcasts/radiolab/articles/great_vaccinator

They had a group of people, some they vaccinated, some they gave saline, all were intentionally exposed to covid to QUICKLY find out what works. Those people volunteered, reducing the ethic issue of this type of test. Same studies have been done with masks, and more intentional studies could also be done. They aren't because scientists know that masks aren't that effective. If they were as effective as vaccines (purported by the CDC "director"), you'd see as rigorous science for masks as vaccines. But you don't because everyone knows masks aren't that effective.

I realize masks are more challenging to test since it's dependent upon the person shedding the virus, but it could be done in natural settings with some control measures. Even something as simple as questionnaires would provide much more insight into effectiveness of masks from a macro level:

• Type of mask
• Frequency of wearing
• Settings
• Time in various settings (indoors, open airflow, outdoors)
• Type of people in setting
• Quantity of people and density

Don't worry about breaking it to me. I have known for years how vaccine studies are done. at

You can't do RCTs for masks because it should be obvious that people know they are wearing a mask and will behave differently. You can't have a "placebo."

Masks do work, but they aren't a 100% solution, just like vaccines are not. Nothing is 100%. But things like vaccines, masks, social distancing, and hygiene all mitigate the spread of COVID

SamHou said:

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Don't worry about breaking it to me. I have known for years how vaccine studies are done. at

You can't do RCTs for masks because it should be obvious that people know they are wearing a mask and will behave differently. You can't have a "placebo."

Masks do work, but they aren't a 100% solution, just like vaccines are not. Nothing is 100%. But things like vaccines, masks, social distancing, and hygiene all mitigate the spread of COVID

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Last year in the U.S. broadly and Texas more specifically, some schools were mask-optional. Other schools forced or coerced children to wear them for hours each day, every day, often even outside during exercise.

Forced-mask schools had higher infection rates than mask-optional. pic.twitter.com/OfPKvOcpDz

— Will Franklin (@WILLisms) August 16, 2021

TarponChaser said:

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SamHou said:

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Don't worry about breaking it to me. I have known for years how vaccine studies are done. at

You can't do RCTs for masks because it should be obvious that people know they are wearing a mask and will behave differently. You can't have a "placebo."

Masks do work, but they aren't a 100% solution, just like vaccines are not. Nothing is 100%. But things like vaccines, masks, social distancing, and hygiene all mitigate the spread of COVID

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Last year in the U.S. broadly and Texas more specifically, some schools were mask-optional. Other schools forced or coerced children to wear them for hours each day, every day, often even outside during exercise.

Forced-mask schools had higher infection rates than mask-optional. pic.twitter.com/OfPKvOcpDz

— Will Franklin (@WILLisms) August 16, 2021

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It would appear those numbers include remote learning schools and students. The fine print matters in this case.

Anecdotally, the preschool and daycare our kids go to, infants through K, has had only a handful of cases in the past 18 months, all coming after the mask requirement was lifted in May. Flu, HFM, and strep also started popping up at the same time. The on-site learning center is for faculty and physicians of the hospital.