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Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

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Re: Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

#121

Post by dragontamer »

kragen wrote: post #105
dragontamer wrote: post #73

Earlier quoted context omitted.

When 70% of people weren't affected by the experiment (13% were wearing masks before the experiment started. 60% of people didn't wear a mask after the experiment), then of course the numbers are going to be small. Seeing a measurable difference when the population only changed from 13% mask to 40%ish mask usage is pretty outstanding IMO.

I don't think that's correct; see https://news.ycombinator.com/item?id=28407881 for the argument in more detail.

My argument and your argument are seemingly unrelated.

That means that the full matrix of situations are available: I'm correct and you're correct. I'm correct and you're wrong. I'm wrong and you're correct, and finally I'm wrong and you're wrong.

----------

So lets just try again from the top. The study shows that an 8-week mask-awareness campaign in Bangladesh across 300 villages (+300 "control" villages 2+km away where mask-awareness did NOT happen) leads to a 29% increase in mask usage and an 11% decrease in COVID19 cases.

Is there anything wrong with this new, revised statement I made? It seems to be the big "A / B" test that everyone's wanted for mask studies.

Re: Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

#122

Post by Animats »

acranox wrote: post #48
majormajor wrote: post #28

Earlier quoted context omitted.

Could you share a link for $1 N95's? That's better than I've seen. I've already moved to this approach myself, it's an increase in cost that I'll gladly take for increased protection. Just waiting for government and businesses in the US to catch up. It was definitely hard to find the good stuff at first - and I was much more reclusive as a result too - but yeah, things have changed. I wish people wouldn't respond to…

https://www.homedepot.com/p/3M-N95-Particulate-Performance-D... Home Depot sells this 20 pack for $24 from 3M. That’s $1.20 each.

Incidentally, if you buy 3M masks, there's a number on the bottom of the box that can be validated on 3M's web site.[1] They will tell you if that's a valid number and if anyone tried to validate that number before.

[1] https://safeguard.3m.com/Guest#/Validation

Re: Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

#123

Post by 908B64B197 »

douglasisshiny wrote: post #13
exabrial wrote: post #6

This is truly great news, as we've need some controlled studies. However, _mandates_, literally threatening people with police violence, bodily or financial harm, is not the correct way forward. I think the best solution is improved mandates for airflow. It's a lot easier to improve airflow in a building than it is to police and enforce a mask mandate.

>However, _mandates_, literally threatening people with police violence, bodily or financial harm, is not the correct way forward. Maybe I'm missing something, but is this actually a thing? Who in the mainstream proposing police violence, bodily or financial harm? The worst I've heard (in the U.S.) is that a business may not allow you to enter if you're not wearing a mask, which is well within their right and reasona…

Someone sent it to me a little while ago.

Enjoy. https://youtu.be/5ByEppIvsDc

Re: Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

#124

Post by belorn »

Its interesting that the article do not mention a rather interesting finding in the study. For the age groups of Why aren't masks effective to reduce the spread for that age group? The discussion part of the study don't explore it. Is the distancing behavior of people aged 50 or higher different than those below?

I would like to see further studies being done on the younger demographic in order to explain why the data is looking like it is.

Re: Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

#125

Post by jasonlaramburu »

treis wrote: post #38
cfn wrote: post #14

Here is the paper (or one of them, it is not clear after so many links): https://www.poverty-action.org/sites/default/files/publicati... Bottom line: "The proportion of individuals with COVID-like symptoms was 7.62% (N=13,273) in the intervention arm and 8.62% (N=13,893) in the control arm. Blood samples were collected from N=10,952 consenting, symptomatic individuals. Adjusting for baseline covariates, the 2 interve…

This is a pretty modest impact, a short duration, and is somewhat clouded by it not being a double blind study. The rate of infection at 7.62% vs 8.62% are particularly troublesome. As a comparison, it's estimated that 1/3-1/2 of Americans have been infected with Covid. It's an open question of what the end game would be. Could be that both groups would end at the same infection rate. The masked group might just take…

How could you possibly construct a double blind study on masks?

Re: Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

#126

Post by nradov »

mrtksn wrote: post #103
fasteddie31003 wrote: post #77

I was militant pro-mask when I was unvaccinated. Now that I'm vaccinated and have no comorbidities, I'm OK with being exposed to COVID-19. In fact, I want to have a mild case of COVID-19 to get natural immunity. Natural immunity seems to be more effective than the vaccine for long lasting immunity.

Because of disparity between states and the large number of anti-vaxxers, We probably will never reach herd immunity which means that Covid-19 will become endemic and everyone will eventually catch it. With the mutations and winding down immunity it is likely to stay with us. So, getting a vaccine significantly reduces the risks of death and and getting exposed to the virus naturally will be our immune booster. That’…

Even if there were fewer anti-vaxxers, the Delta variant is so contagious that we won't be able to reach a level of herd immunity sufficient to protect unvaccinated people. All of us can expect to be exposed eventually.

https://www.businessinsider.com/delta-variant-made-herd-immu...

Re: Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

#127

Post by polote »

ch4s3 wrote: post #3

> There were significantly fewer COVID-19 cases in villages with surgical masks compared with the control villages. (Although there were also fewer COVID-19 cases in villages with cloth masks as compared to control villages, the difference was not statistically significant.) This aligns with lab tests showing that surgical masks have better filtration than cloth masks. However, cloth masks did reduce the overall like…

At the end of the day if the reduction is 11%, even if that works (because that reduce by 11%) that is still useless in order to control the epidemic. Unless we find 10 measures like that. But what they show is probably not the same that the impact of mask mandate or an `always wear mask` at the personal level. So not much is applicable about that study. Only that mask kind of reduce covid spread

Re: Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

#128

Post by GeekyBear »

timr wrote: post #62
GeekyBear wrote: post #36

Cloth masks are quite effective against viruses with a droplet based spread. Widespread mask use came as close to wiping out last year's Flu season as we've ever seen. >Amid COVID-19 pandemic, flu has disappeared in the US NEW YORK (AP) — February is usually the peak of flu season, with doctors’ offices and hospitals packed with suffering patients. But not this year. Nationally, “this is the lowest flu season we’ve h…

> Widespread mask use came as close to wiping out last year's Flu season as we've ever seen. This is an assertion. It could have been the fact that nobody was traveling last year. It could have been the fact that most kids were out of school. It could have been distancing. It could have been any number of other things. Any conclusion here is premature.

The conclusion that cloth masks are ineffective against viruses with an airborne spread, while a properly worn n95 mask does provide real protection is hardly premature.

Here's the quote above from one of the scientists on President Biden's Covid advisory board in context:

>Needless to say, masking is political hot button beyond anything I've ever seen in public health.

At the same time i think we've all done a disservice to the public.

When you actually look at face cloth coverings, they actually only have very limited impact in reducing the amount of virus that you inhale in or exhale out.

Studies that have been done show that if an individual might get infected within 15 minutes in a room, by time and concentration of the virus in the room, add a face cloth covering you only get about five more minutes of protection.

I've been really disappointed with my colleagues in public health for not being more clear about what can masking can do or not do.

On the other hand if you use the n95 respirators and fit them tight to your face, you can actually spend 25 hours in that same room and still be protected.

The bottom line though is by telling people that in fact just putting a face cloth covering on is going to protect you is simply not true.

https://www.pbs.org/wnet/amanpour-and-company/video/do-masks...

People are flailing away to claim that cloth masks "do so do something" in a very counterproductive way. I'm reminded of Ivermectin proponents.

Re: Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

#129

Post by mdp2021 »

908B64B197 wrote: post #118
majormajor wrote: post #11

Earlier quoted context omitted.

It's surprising to me that cloth masks can't even do the 11% of surgical masks. Which isn't much, but surgical masks are non-optimal for many reasons. Not to mention that this doesn't seem the same as "while wearing a surgical mask you only get 11% increase in protection" but is a population-level thing. There was still non-compliance that presumably lowered the efficacy. I would've intuitively guessed that the bette…

"Cloth masks" can mean anything. I wish early in the pandemic someone would have made some piece of equipment to asses whether a given cloth mask is good or not. Most people have a few now and I'm sure they would like to use the best one.

> "Cloth masks" can mean anything [...]

I guess the point is "not certified".

Re: Surgical masks reduce Covid-19 spread, large-scale Stanford study shows

#130

Post by jasonlaramburu »

belorn wrote: post #124

Its interesting that the article do not mention a rather interesting finding in the study. For the age groups of Why aren't masks effective to reduce the spread for that age group? The discussion part of the study don't explore it. Is the distancing behavior of people aged 50 or higher different than those below? I would like to see further studies being done on the younger demographic in order to explain why the dat…

Maybe lower mask adherence among younger people or different behaviors-- older people in villages might stay at home more.
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