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Covid19 redux


Bosco-d-gama

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Well, if you sneeze or cough into something that covers your face, that extra layer might help protect others around you. Actually, I would be cutting up a HEPA filter for that. We are looking at patterns right now. I just want to use double or triple folded pieces of 600 count cotton sheets. If you can see sunlight through it, or if it can't survive being washed a hundred times, it's worthless.

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From this article:

 

Surgical masks are loose pieces of fabric placed in front of the mouth and nose...

 

4. Do surgical masks prevent ordinary people from getting infected outside the healthcare setting?

The same review lists nine randomized trials with a different design: when the doctor diagnoses you with flu, she either asks everyone in your family to wear masks (experimental group), or doesn’t do that (control group), and then checks how many family members in each group got the flu.

 

How did these go? That depends whether you use intention-to-treat or per-protocol analysis. Intention-to-treat means that you just compare number of infections in the assigned-to-wear-masks group vs. the control group. Per-protocol means that you only count someone in the study if they actually followed directions. So if someone in the assigned-to-wear mask group didn’t wear their mask, you remove them from the study; if someone in the control group went rogue and did wear a mask, you remove them too.

 

Both of these methods have their pros and cons. Per protocol is good because if you’re trying to determine the effect of wearing a mask, you would really prefer to only be looking at subjects who actually wore a mask. But it has a problem: adherence to protocol is nonrandom. The people who follow your instructions diligently are selected for being diligent people. Maybe they also diligently wash their hands, and diligently practice social distancing. So once you go per protocol, you’re no longer a perfect randomized controlled trial. Only intention-to-treat analyses carry the full weight of a gold standard RCT.

 

According to intention-to-treat, the studies unanimously found masks to be useless. But there were a lot of signs that intention-to-treat wasn’t the right choice here. Only about a fifth of people who were asked to wear masks did so with any level of consistency. The rest wore the mask for a few hours and then get bored and took it off. Honestly, it’s hard to blame them; these studies asked a lot from families. If a husband has flu, and sleeps in the same bed as his wife, are they both wearing masks all night?

 

Of the three studies that added per-protocol analyses, all three found masks to be useful (123) . Does this prove masks work? Not 100%; per-protocol analyses are inherently confounded. But it sure is suggestive.

 

The review author summarizes:

The routine use of facemasks is not recommended by WHO, the CDC, or the ECDC in the community setting. However, the use of facemasks is recommended in crowded settings (such as public transport) and for those at high risk (older people, pregnant women, and those with a medical condition) during an outbreak or pandemic. A modelling study suggests that the use of face-masks in the community may help delay and contain a pandemic, although efficacy estimates were not based on RCT data. Community masks were protective during the SARS outbreaks, and about 76% of the population used a facemask in Hong Kong.

There is evidence that masks have efficacy in the community setting, subject to compliance [13] and early use [12, 18, 19]. It has been shown that compliance in the household setting decreases with each day of mask use, however, which makes long term use over weeks or months a challenge […]

Community RCTs suggest that facemasks provide protection against infection in various community settings, subject to compliance and early use. For health-care workers, the evidence suggests that respirators offer superior protection to facemasks.

Parts of this summary are infuriating. If the big organizations recommend that especially vulnerable groups wear masks, aren’t they admitting masks work? But if they’re admitting masks work, why don’t they recommend them for ordinary people?

 

It looks like they’re saying masks work a little, they’re too annoying for it to be worth it for normal people, but they might be worth it for the especially vulnerable. But then why don’t they just say masks work, and let each person decide how much annoyance is worthwhile? I’m not sure. But it looks like the author basically ends up in favor of community use of surgical masks in a pandemic, mostly on the basis of per-protocol analyses of community RCTs.

 

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2 minutes ago, Deang said:

If you can't maintain social distancing, they are a necessary evil I think -- but they only have any real efficacy if everyone is wearing them.

 

 

Here is the key takeaway from the article quoted above:

 

Quote

Of the three studies that added per-protocol analyses, all three found masks to be useful (123) . Does this prove masks work? Not 100%; per-protocol analyses are inherently confounded. But it sure is suggestive.

 

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17 minutes ago, Jeff Matthews said:

From this article:

 

Surgical masks are loose pieces of fabric placed in front of the mouth and nose...

 

4. Do surgical masks prevent ordinary people from getting infected outside the healthcare setting?

The same review lists nine randomized trials with a different design: when the doctor diagnoses you with flu, she either asks everyone in your family to wear masks (experimental group), or doesn’t do that (control group), and then checks how many family members in each group got the flu.

 

How did these go? That depends whether you use intention-to-treat or per-protocol analysis. Intention-to-treat means that you just compare number of infections in the assigned-to-wear-masks group vs. the control group. Per-protocol means that you only count someone in the study if they actually followed directions. So if someone in the assigned-to-wear mask group didn’t wear their mask, you remove them from the study; if someone in the control group went rogue and did wear a mask, you remove them too.

 

Both of these methods have their pros and cons. Per protocol is good because if you’re trying to determine the effect of wearing a mask, you would really prefer to only be looking at subjects who actually wore a mask. But it has a problem: adherence to protocol is nonrandom. The people who follow your instructions diligently are selected for being diligent people. Maybe they also diligently wash their hands, and diligently practice social distancing. So once you go per protocol, you’re no longer a perfect randomized controlled trial. Only intention-to-treat analyses carry the full weight of a gold standard RCT.

 

According to intention-to-treat, the studies unanimously found masks to be useless. But there were a lot of signs that intention-to-treat wasn’t the right choice here. Only about a fifth of people who were asked to wear masks did so with any level of consistency. The rest wore the mask for a few hours and then get bored and took it off. Honestly, it’s hard to blame them; these studies asked a lot from families. If a husband has flu, and sleeps in the same bed as his wife, are they both wearing masks all night?

 

Of the three studies that added per-protocol analyses, all three found masks to be useful (123) . Does this prove masks work? Not 100%; per-protocol analyses are inherently confounded. But it sure is suggestive.

 

The review author summarizes:

The routine use of facemasks is not recommended by WHO, the CDC, or the ECDC in the community setting. However, the use of facemasks is recommended in crowded settings (such as public transport) and for those at high risk (older people, pregnant women, and those with a medical condition) during an outbreak or pandemic. A modelling study suggests that the use of face-masks in the community may help delay and contain a pandemic, although efficacy estimates were not based on RCT data. Community masks were protective during the SARS outbreaks, and about 76% of the population used a facemask in Hong Kong.

There is evidence that masks have efficacy in the community setting, subject to compliance [13] and early use [12, 18, 19]. It has been shown that compliance in the household setting decreases with each day of mask use, however, which makes long term use over weeks or months a challenge […]

Community RCTs suggest that facemasks provide protection against infection in various community settings, subject to compliance and early use. For health-care workers, the evidence suggests that respirators offer superior protection to facemasks.

Parts of this summary are infuriating. If the big organizations recommend that especially vulnerable groups wear masks, aren’t they admitting masks work? But if they’re admitting masks work, why don’t they recommend them for ordinary people?

 

It looks like they’re saying masks work a little, they’re too annoying for it to be worth it for normal people, but they might be worth it for the especially vulnerable. But then why don’t they just say masks work, and let each person decide how much annoyance is worthwhile? I’m not sure. But it looks like the author basically ends up in favor of community use of surgical masks in a pandemic, mostly on the basis of per-protocol analyses of community RCTs.

 

 

 

Jeff,

 

If someone is admitted to the Hospital and we know they have flu...

 

The yare placed in a negative pressure room if one is available and everyone wears N-95 masks, eye protection, gowns and gloves.

 

Roger

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3 minutes ago, Jeff Matthews said:

BTW, Carl's link to the video of Fauci's former employee is no good anymore.  Youtube took down the video.  

 

 

I knew they would ...

 

 They are left leaning and NOT about free speech.

 

They want to control the narrative.

 

Roger

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1 minute ago, 314carpenter said:

Thread is full of misinformation again. Time for a repost for the straight facts.

 

https://www.lung.org/blog/update-covid-19

 

From your link:

Quote

The CDC recently changed guidelines to recommend that individuals wear a cloth face covering when out in public, such as a grocery store, to further reduce the transmission of the virus. Commercial masks, such as N95 masks, are not recommended as they are urgently needed by healthcare providers caring for sick individuals. 

 

As the surgeon general stated, the recommendation of wearing cloth face coverings is to protect others from your respiratory droplets when cough, sneeze or talk because we know that people with little to no symptoms can unknowingly spread the disease.  The cloth covering is not being recommended as a way for you to decrease getting infected—the main way you protect yourself is avoiding others who are sick, maintaining social distancing, washing your hands frequently and not touching your face (nose, mouth, eyes) and cleaning regularly used surfaces and objects with disinfecting products.

 

Read the takeaway points very carefully.  Nothing says face coverings don't work.  It says cloth coverings are recommended.  It also says they are not substitutes for distancing, washing hands, etc.

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3 minutes ago, twistedcrankcammer said:

 

 

I knew they would ...

 

 They are left leaning and NOT about free speech.

 

They want to control the narrative.

 

Roger

It's bizarre to me.  I wonder what their stated position would be if asked to directly state why.

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27 minutes ago, Deang said:

Well, if you sneeze or cough into something that covers your face, that extra layer might help protect others around you. Actually, I would be cutting up a HEPA filter for that. We are looking at patterns right now. I just want to use double or triple folded pieces of 600 count cotton sheets. If you can see sunlight through it, or if it can't survive being washed a hundred times, it's worthless.

Merv 19 A/C Air filters.

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1 minute ago, 314carpenter said:

Thread is full of misinformation again.

And I was just getting some confidence in the information I was getting here ... we were nearly on par with the National Enquirer for a short time. 

There are some smart, seemingly well-balanced people here, some that enjoy acting like jerks, and there are some buffoons. I think it's easy to spot each. 

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