Comment by __blockcipher__ | Hacker News Reader

Comment by __blockcipher__ | Hacker News Reader

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__blockcipher__

> It's been conclusive for years and years, before COVID-19

What? The overwhelming literature showed the exact opposite! That cloth masks did not prevent Influenza whatsoever.

I'd start with https://aapsonline.org/mask-facts/ as a great review, and then take a look at some specific studies like this one:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4420971/

> The rates of all infection outcomes were highest in the cloth mask arm, with the rate of ILI statistically significantly higher in the cloth mask arm (relative risk (RR)=13.00, 95% CI 1.69 to 100.07) compared with the medical mask arm. Cloth masks also had significantly higher rates of ILI compared with the control arm. An analysis by mask use showed ILI (RR=6.64, 95% CI 1.45 to 28.65) and laboratory-confirmed virus (RR=1.72, 95% CI 1.01 to 2.94) were significantly higher in the cloth masks group compared with the medical masks group. Penetration of cloth masks by particles was almost 97% and medical masks 44%.

> This study is the first RCT of cloth masks, and the results caution against the use of cloth masks.

> The control arm was ‘standard practice’, which comprised mask use in a high proportion of participants. As such (without a no-mask control), the finding of a much higher rate of infection in the cloth mask arm could be interpreted as harm caused by cloth masks, efficacy of medical masks, or most likely a combination of both.

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The TL;DR is masks were never thought to work for community transmission of any respiratory virus, but they definitely don't work for SARS-2 where the preponderance of evidence points to aerosol transmission as the dominant transmission mode, which masks cannot help against and could theoretically worsen (by increasing the total quantity of aerosols released, and that's before looking at factors like them giving a false sense of security or requiring conversational partners to stand more closely together)

>I'd start with https://aapsonline.org/mask-facts/ as a great review, and then take a look at some specific studies like this one:

for one, this was last updated a year ago. That's OK -- but it's jam-packed with 'citations' (many are from non-medical groups like NY Times, so on) from 2020, around 50 of them. Much of the data changed, was redacted, or non-reproducible by other groups.

I read through it until I came upon the second or third 'conclusion' that was at odds with the conclusion of the paper-authors she cites.

The 'curator' of that data is an anesthesiologist who 'teaches constitutional law to non-lawyers', and posts political blogs regarding 'mainstream media propaganda regarding the vaccine and ivermectin' and articles that refer to Kamala Harris as 'another snake slithering out of the swamp'.[0]

Her conclusions may be right, it may be wrong -- but the political axe being ground, combined with the conclusion/data inaccuracies portrayed against the cited works, leads me to believe -- anecdotally -- that the opinions are likely unreliable and biased; it prompts me to want to find other professionals to consult.

[0]: https://marilynsingletonmdjd.com/category/politics/page/5/

Where did your conclusion of "masks definitely don't work for SARS-2" come from? Just in your quote it stated that the control that cloth mask use was compared to was a population with a high proportion of mask wearing. The study does not compare cloth mask usage to no mask usage, and only says that it is possible that cloth masks are harmful.

Also if you would like some more up to date information, as well as a larger number of studied, which are specific to COVID, the CDC website has a lot of information here:

https://www.cdc.gov/coronavirus/2019-ncov/science/science-br...

> Just in your quote it stated that the control that cloth mask use was compared to was a population with a high proportion of mask wearing. The study does not compare cloth mask usage to no mask usage, and only says that it is possible that cloth masks are harmful.

That was me debunking the “before COVID, masks were known to work” claim of the GP. That was not a study of SARS-2 but rather Influenza.

The “masks don’t work for sars-2” was in reference to sars-2 aerosol transmission, which masks mechanistically don’t protect against. There is only one RCT of sars-2 in a community setting, and it failed to demonstrate an improvement in the primary endpoint of self-infection. There is no study showing that masks slow the spread of sars-2 in a community. Yet despite the lack of any studies, various medical authorities like the CDC are issuing statements that they do exactly that, which is a classic case of an institution using its credibility to advance baseless claims

> There is no study showing that masks slow the spread of sars-2 in a community

You say that, and yet "At least ten studies have confirmed the benefit of universal masking in community level analyses"

https://www.cdc.gov/coronavirus/2019-ncov/science/science-br...

And the website goes on to list each of them, as well as a number of other studies relating to the effectiveness of masking.

Those studies all have fundamental flaws. The basic problem is those are associative studies, which can’t separate the effects of masking from the normal curve of a viral epidemic.

You are right though I should have been much more specific than just “study”.

A question though: if masking is so great, why wouldn’t the health authorities have performed an actual RCT to conclusively prove they work? (We have one RCT for SARS-2 which showed no statistically significant effect on the primary endpoint)

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