To mask or not to mask?

[Arnold]

Next week I will be traveling twice as far as I need to to get to Nashville from Philly, yes that's right I'm riding in a tubular aluminium germ incubator assembled by Boeing.

Should I wear a surgical mask or not?

Some thoughts:

1) I am just as handsome with and without the mask.

2) I don't know if they are effective.
3) Does anyone know if they are effective?

4) These are a professional model mask donated by a dental school.

All input accepted - talk to the mask.

 

[PeterNSteinmetz]

Yeah and 40 % thought Ebola would be a major outbreak here. Just like with this virus, your chances are still greater from dying from the flu than coronavirus. Rational preparation is fine but I think there’s a lot of overreacting going on right now.

Probably. I just wish I had bought stock in the companies that make the N95 masks earlier.

 

[PeterNSteinmetz]

“The evidence is not sufficiently strong to support widespread use of facemasks as a protective measure against COVID-19. However, there is enough evidence to support the use of facemasks for short periods of time by particularly vulnerable individuals when in transient higher risk situations."

Results of a quick google scholar search produced a number of articles in the actual medical scientific literature regarding the effectiveness of cloth masks in slowing the spread of respiratory infections like Covid-19.

Here is one in the British Medical Journal, April 7, 2020. "Covid-19: What is the evidence for cloth masks?" https://www.bmj.com/content/369/bmj.m1422.short

In discussing a systematic review of this question, which is a preprint available at https://www.medrxiv.org/content/10.1101/2020.04.01.20049528v1 the authors of that review state in full (excerpt above)

"Based on the RCTs we would conclude that wearing facemasks can be very slightly protective against primary infection from casual community contact, and modestly protective against household infections when both infected and uninfected members wear facemasks. However, the RCTs often suffered from poor compliance and controls using facemasks. Across observational studies the evidence in favour of wearing facemasks was stronger. We expect RCTs to under-estimate the protective effect and observational studies to exaggerate it. The evidence is not sufficiently strong to support widespread use of facemasks as a protective measure against COVID-19. However, there is enough evidence to support the use of facemasks for short periods of time by particularly vulnerable individuals when in transient higher risk situations. Further high quality trials are needed to assess when wearing a facemask in the community is most likely to be protective."

My view is pretty much in exact agreement with the authors of that preprint. Also please note that the authors did not in any way consider the possible negative consequences of making a broad scale community recommendation to wear cloth masks.

 

[PeterNSteinmetz]

Both of those citations seem to refer to the same study.

No, did you look at the articles?

Both quotations are from the second one, which was the quick review of the literature (as noted the first quote is an excerpt from the second)

The first reference is the BMJ article which cited the quick review and other articles, as well as quoting a number of experts on why cloth masks may not work so well.

The quick review of course cites a fair amount of other literature.

 

[PeterNSteinmetz]

Of course I did. One even quoted the other. Both citations appear to be from from BMJ, the second one has the BMJ logo on it. It's the same group.

The first article is essentially a commentary in the BMJ by Mahase. That article references and quotes the second article, a preprint, which is a rapid review of the literature by a a different set of authors. The BMJ commentary also quotes a different set of experts.

Contrast https://www.bmj.com/content/369/bmj.m1422 versus https://www.medrxiv.org/content/10.1101/2020.04.01.20049528v1

These are two very different types of articles, a commentary versus a rapid review. The preprint has not been published yet so far as I know.

So no, both citations were not to the same article. The quotations were both from the rapid review, with the leading quotation being an excerpt from the larger quotation, as noted.

Perhaps some of the apparent confusion here may be due to a difference between formal academic citation practice and lay interpretation.

In any case, I found both articles informative in somewhat different ways which is why I shared them both.

I think the rapid review did a fairly good job of summarizing the available evidence at that time, early April. The comments by the experts in the BMJ article are informative as to why theoretical advantages of cloth masks, such as those studied in the Nature article which you cited, may not translate to slowing the spread of Covid-19.

 

[PeterNSteinmetz]

In any case, it doesn't matter to me. I have a few masks. If a store wants people to wear masks while inside, I don't see it as a big deal. If you have an issue with it, don't go to those places.

Agreed that if a private store wants to require masks, that is their business. If you don’t like it, either shop somewhere else, complain to management, or do both.

I just think it is ridiculous all the people one sees one social media being outraged that others are not wearing cloth masks in public.

 

[PeterNSteinmetz]

However, as mentioned below... it appears the study is backwards. The masks are intended to protect others, who aren't yet infected, from those who might be.

The rapid review covered articles looking at both sides of the equation. In other words, at whether the wearer was protected and whether others were protected from the wearer.

It concluded that there was not enough good information to make a recommendation for general public use at that time. (Sentence just before the one you bolded.) Also again in the discussion at the end of the review they state “We do not consider that the balance of evidence across all available studies supports routine and widespread use of facemasks in the community.”

Agreed that the study you cited provides theoretical reasons to think mask wearing might protect others. And there is a long standing recommendation to provide surgical masks for those who are known to have an active respiratory infection, particularly those who are coughing or sneezing. But that does not directly show that wearing cloth masks will reduce the spread of Covid-19 when worn by the general public. I am not aware of any empirical studies which suggests that the general public wearing cloth masks will achieve that goal.

 

[PeterNSteinmetz]

Although applicability to the current situation is shown here, where some measurements seem to have been done:
https://www.nature.com/articles/s41591-020-0843-2

One of the important limitations in this study in terms of a recommendation for the general public is that all participants were actively ill. So the implications for the general public are weaker given that most of them will not be actively ill.

 

[PeterNSteinmetz]

TL;DR
Not as good as surgical masks, but better than nothing.

I think one really has to read the articles and understand them to determine whether they imply that a recommendation for the general public to wear cloth masks will actually slow the spread of Covid-19 and thus be “better than nothing”.

If one is not willing or able to do that, then likely best to rely on the impressions expressed by experts in published commentaries or reviews.

Of those so far, none have concluded there is good evidence to recommend the use of cloth masks for the general public.

 

[PeterNSteinmetz]

Like I said, no consensus as yet:
https://www.theguardian.com/world/2020/may/04/scientists-disagree-over-face-masks-effect-on-covid-19

Firstly, the Guardian is not a scientific journal like the British Medical Journal. It does refer to a preprint however. Many of the experts quoted by the Guardian were highly skeptical of the conclusions the authors of the preprint drew, saying they over-stated the evidence and ignored the possibility that wearing cloth facemasks generally could do harm.

Thus I would not consider the pre-print indirectly cited to be even good evidence for a public health recommendation for the general public to use cloth masks. OTOH, it would be fair to say there is some segment of the scientific community which thinks they might work.

Now to get to the bottom of an evolving issue like this one has to actually read and understand and critically think about the reviews and the primary research articles available.

Short of doing that, I think the conclusions of the brief review I cited are a pretty balanced summary.

 

[PeterNSteinmetz]

URL]

Some of the confusion is because some cloth masks are better than others, depending on the materials used:
https://pubs.acs.org/doi/10.1021/acsnano.0c03252

True, there is likely a great deal of variability, particularly amongst the make commonly being made and used by the general public in the US, both in terms of the materials and the level of seal achieved.

Yes, only the "ill" ones really need a mask. But given that some people are asymptomatic, yet "actively ill", there is still a degree of protection from those people.

This deals with a very important issue that likely limits the utility of masks worn by the general public and must be considered when making a public health recommendation.

People who have recently been infected are likely only shedding the virus in significant amounts and by routes likely to impact others for perhaps 1-2 weeks.

This is why it is important to rely on actual measurements of the effects in the real world rather than just theory.

 

[PeterNSteinmetz]

Most people will get their data from The Guardian, WHO, or the CDC web sites.

OK, let me clarify further. I think it is best to be able to actually evaluate the data and analyses, but short of that to rely on published reviews and commentaries in the scientific literature. I do not think it is wise for individuals to rely upon commentaries in popular publications like The Guardian. Sorry if it was not clear that as a scientist I would be referring to the scientific literature, but I hope that clarifies.

In terms of recommendations by public health authorities, the recommendations regarding public mask wearing is mixed. CDC presently recommends that and the WHO does not (https://www.who.int/emergencies/dis...9/advice-for-public/when-and-how-to-use-masks).

I disagree about the conclusions of the brief review, it was rather one-sided.

Well, to parse further which pre-print reviews are better one really would have to go and examine the articles they reference, read, and understand them. But apparently that is TL;DNR. So I really don't know how we could have a meaningful conversation about what the different reviews have concluded. We will likely just have to agree that you disagree with those experts then.

My point is that the USA had time to evaluate this thing that we wasted. The theory is good enough, given this is an airborne virus. The earlier citations looked at influenza and earlier corona viruses, and except for the number of people affected this time, the information from those outbreaks can certainly be applied. My experience supports the reports cited that the USA actually also knew of the virus. I agree that the studies you suggest would be best, but we ****ed that time away.
View attachment 85879

Sort of trending off the issue of current recommendations of public mask usage. I would agree that perhaps at that time, given the scary stories were were hearing, that some type of emergent intervention might have been reasonable. But by the time the coercive lockdowns were being put in place, there was already a ton of social distancing occurring, we knew those really scary numbers probably weren't true, and we should have waited for more data. I also note that there is no good empirical evidence that the coercive lockdowns have reduced the number of cases or deaths due to Covid-19, as I have discussed extensively in the "Did you get it?" thread. Let's move further discussion of that over there if you want to go over those issues.

 

[PeterNSteinmetz]

I disagree about the conclusions of the brief review, it was rather one-sided.

This actually brings me to a question I have wanted to ask. It is related but deals with personal opinion, so feel free to ignore if you want.

Why do you want to think that cloth mask wearing by the public will help stop the spread of Covid-19? Is it because it is something that might help that people can do? Or have you been forced to wear them by an employer?

 

[PeterNSteinmetz]

Just looking again at the WHO recommendation. Striking actually in its contraction of the CDC

"If you are healthy, you only need to wear a mask if you are taking care of a person with COVID-19.

• Wear a mask if you are coughing or sneezing.
• Masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water.
• If you wear a mask, then you must know how to use it and dispose of it properly."

 

[PeterNSteinmetz]

I don't find them onerous, but it seems some people posting in this thread do apparently find them extremely uncomfortable.

Most of the people I have discussed them with find them quite uncomfortable to wear for an 8 hour shift.

My objections do not have to do with discomfort. They are two-fold.

Firstly, there are now a whole bunch of people on social media sites trying to act like anyone who doesn't wear a mask is a sociopath. Since I regard the evidence that mask wearing by the general public will help control the spread of Covid-19 as very weak or generously as "mixed", I view that as a form of bullying -- that is -- trying to intimidate or harass people into doing things they do not personally choose to do in public in order to help that person alleviate some fear they have.

Secondly, I also have a very low tolerance for how policy decisions made in this country by politicians often have almost no justification in the actual empirical evidence. I am particularly offended when politicians try to coerce people into doing things without evidence that there is a clear danger of people threatening to or actually harming others.

 

[PeterNSteinmetz]

I can't parse that. Some people, prevented from entering a business without masks, have harmed others.
https://www.nytimes.com/2020/05/08/us/coronavirus-masks-dollar-store-shooting-flint-Michigan.html
Or the business following the law:
https://www.cnn.com/2020/05/06/us/mcdonalds-employees-shot-coronavirus/index.html
So there's a lot of stupidity on both sides of the discussion.

I think people shooting each other over a dispute related to Covid-19 is clearly a different situation. The use of deadly force is in my view only justified by private individuals when facing a clear present threat of serious bodily injury or death.

But here is my view of when we are justified coercing other people to do things they don’t want to otherwise do. Perhaps it will help with the parsing of my meaning.

Firstly if someone has harmed others and that is provable beyond a reasonable doubt then we are justified in coercing the aggressor. Secondly if someone is clearly threatening to imminently harm others, we can use the minimal amount of coercion to prevent them from doing so.

In the case of wearing masks and Covid-19, for asymptomatic individuals the risk of them harming someone else in a public place are just too low to justify coercion. Doesn’t meet the standard of clear threat of imminent harm and using minimal coercion to prevent the harm. That is due to a combination of factors - the low rate of catching Covid-19 from casual interactions in the first place, the low infection fatality rate, and the poor evidence that requiring a mask will prevent the infection. The risk of serious harm is about on the order of daily living or lower for someone choosing to interact in public with 1 person per day with unknown infection status (admittedly that is a very rough estimate).

The risks in voluntary interactions, such as businesses, may be different and don’t enter into my evaluation of coercing people to wear masks as those are voluntary interactions.

Someone deliberately choosing to try and infect someone would also be a different case in terms of coercion.

 

[PeterNSteinmetz]

On the other hand, there's nothing to recommend NOT wearing the maskes.

Actually one might want to see the expert comments in the BMJ commentary I cited. Several of them are concerned precisely about the possible negative consequences of making a general recommendation to wear cloth masks. That is why some scientists believe such a general recommendation should not be made.

 

[PeterNSteinmetz]

@PeterNSteinmetz

Broaden your search. Asia has repeatedly found masks work. This is how with high density cities they have lower COVID-19 and lower influenzas and other respitory spread.
Now, they do not have lab tests to verify. But they have results.

Tim

Sent from my HD1907 using Tapatalk

Hi Tim. I am familiar with that literature. I do not regard it as particularly persuasive on this point for a variety of reasons and continue to agree with the conclusion of the Brainerd et al review that the totality of the evidence does not support issuing a recommendation to the general public to wear cloth masks.

This is in agreement with the recommendation of the World Health Organization but at variance with the recommendation by the US CDC.

Overall, there simple is not scientific consensus on this point at this time. And frankly I don’t know that there will be without further empirical studies.

 

[PeterNSteinmetz]

I was thinking about this more today on my walk and it occurs to me that much of the ire about whether other people should wear masks can hopefully largely go away when an adequate supply of N95s and respirators is available.

I mean if you can protect yourself at the level you desire in public relatively easily then what business should it then be of yours whether someone else wants to wear a mask or not?

So maybe this is a fairly temporary issue.

 

[PeterNSteinmetz]

That level of protection is a new mask and disposal after each sojourn.
If you have done the research you state you would know first that n95 is not panacea but one piece of the puzzle.
Second, the cost at 15 each in bulk would consume a very significant percentage of the income for those who can least afford it.
While a simple cloth mask is reusable and costs a couple bucks.

Tim

Sent from my HD1907 using Tapatalk

Yes, “adequate supply” would mean at a price affordable to people. Respirators would likely be better protection since they cover the eyes as well. We are a ways from that level of availability.

I am actually not sure this is the way it will resolve though. My observation is that people are just decreasing mask usage, primarily their cloth masks, significantly. I suspect people are just getting fed up with whole situation and a majority won’t worry about this level of risk in daily life.