# Cloth Masks Are Comfort Blankets according to SAGE committee member



## pm133 (Jul 17, 2021)

Finally, some sanity regarding masks from a member of Sage who advise the government.
I've been banging on about this for over a year now and it's nice to see someone in authority finally publicly saying it.

My criticism? Where was this guy a year ago before medics were allowed to control the narrative regarding this masking obsession? Why are these people so damn slow?

https://www.telegraph.co.uk/news/2021/07/17/cloth-face-masks-comfort-blankets-do-little-curb-covid-
spread/?WT.mc_id=tmgliveapp_iosshare_AxdbmR7tGYPz

_Dr Axon said the public need to be offered a wider view of the science behind face masks, rather than the "partial view" of information being pushed by medics over their effectiveness.
'Medics have a cartoonish view of how the world is'
"Medics have this cartoonised view of how particles move through the air - it's not their fault, it's not their domain - they've got a cartoonish view of how the world is," he said.
"Once a particle is not on a biological surface it is no longer a biomedical issue, it is simply about physics. The public has only a partial view of the story if information only comes from one type of source. Medics have some of the answers but not a whole view."_

*"Masks can catch droplets and sputum from a cough but what is important is that SARS CoV-2 is predominantly distributed by tiny aerosols."*


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## everydayupsanddowns (Jul 18, 2021)

I have always felt that cloth masks were never going to be 100% effective is stopping all possible spread of virus from me if I asymptomatically had it.

But I choose to continue to wear them because I believe they will have an effect of stopping the majority of droplets and SOME aerosols (including water vapour which I can feel as I wear one). 

I believe they also serve as a useful visual reminder to others that there is an ongoing health concern with rising infection rates.

I’m less worried about surface transmission these days, but still choose to be cautious eg wiping down a supermarket trolley handle.

It seems to be it’s about attempting to reduce virus load. My understanding is that infection doesn’t happen because we come into contact with one single particle. We need exposure to a reasonable ‘dose‘. 

So if by wearing a mask I can reduce the flow of aerosols from 100% and limit it to a few which leak out the edges, that seems worthwhile?


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## pm133 (Jul 18, 2021)

everydayupsanddowns said:


> I have always felt that cloth masks were never going to be 100% effective is stopping all possible spread of virus from me if I asymptomatically had it.
> 
> But I choose to continue to wear them because I believe they will have an effect of stopping the majority of droplets and SOME aerosols (including water vapour which I can feel as I wear one).
> 
> ...



You are correct about them being a visual reminder. That is why their use was mandated last year.

You also mention reducing the viral load. So that scientist is talking about the holes in the mask being 500,000 times bigger than the particles containing covid.

If you imagine that the covid soaked particle is the size of a basketball, that's like throwing the ball at a net which has holes the size of Belgium and expecting the ball to stick in the net. You really are going to catch virtually nothing. If anyone believes otherwise and wants to continue wearing a mask, they are very welcome to do so but the Physics is crystal clear on this. Also, it's not my place to tell you not to wear masks.

You are correct that the biggest droplets of a sneeze or a cough will largely be caught but a very significant amount of both are also tiny invisible particles and you have the same problem.

That is why scientists are telling us to ventilate indoor spaces. These things hang in the air for significant periods of time. Large sneeze and cough droplets don't do that. they fall to the ground and surfaces like tables. If this was the source of covid, then wiping surfaces would have pretty much stopped it.

If someone with covid enters a pub and breathes out, I'm afraid that everyone in that pub is probably getting a dose.

The issue here is that there are extremely vulnerable people who now wrongly believe these masks work and will go into places which could be dangerous for them.

Incidentally, those green surgical style masks we all wear are no better. They are not designed to catch small particles either.

The best advice for avoiding covid is to avoid indoor spaces, whether people are masked up or not. That's the advice which needs to be sent to Clinically Extremely Vulnerable people and the government are not doing a good enough job of getting that message out there.


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## pm133 (Jul 18, 2021)

As people in England move into tomorrow, the big worry for me is that so many have turned this into an issue of "morality" that we're inevitably going to see confrontation, especially on public transport. Some of that confrontation is going to end up turning violent.
I think that London is going to be an extremely challenging place to travel thanks to the Mayor over-ruling the government all on his own but without having the law to back up the people who are going to have to enforce his wishes.

The tragedy here is that it's all going to be over a piece of cloth which does nothing anyway.

People who want to mask up are not sheep. They are making a free choice and should be left alone to do so if that's what they want.
Equally, people who don't wear masks are not "heartless bastards who want to see people die so thay can have a pint". They also should be left to make their own choices without interference from others.

I hope that after Monday, a lot of the debate on this stuff fades away because what's been corrupted and lost in all of this is the science. Sadly, I don't think the public reputation of science will recover from this. It was refreshing to see a proper scientist with actual expertise in Physics finally speak out about the reality behind masks in that article I posted but sadly it's too little and more than a year too late. People are no longer listening I suspect. They've bought into the story about "every little helps" and they've switched off to reason. That's a real shame.


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## Docb (Jul 18, 2021)

The problem i find with this lot is that I have no idea just how useful masks are and i suspect those for them and those against them have no real idea either.  The arguments for and against mask wearing make perfect sense in isolation but lead to irresolvable debate when set against each other.  All you have is a shouting match based on opinion.

Wish there were some real definitions of terms and numbers that compared alternative approaches against those definitions.


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## Lucyr (Jul 18, 2021)

The issue of morality and potential confrontation is why i'll probably continue wearing my exemption lanyard


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## Eddy Edson (Jul 18, 2021)

Docb said:


> The problem i find with this lot is that I have no idea just how useful masks are and i suspect those for them and those against them have no real idea either.  The arguments for and against mask wearing make perfect sense in isolation but lead to irresolvable debate when set against each other.  All you have is a shouting match based on opinion.
> 
> Wish there were some real definitions of terms and numbers that compared alternative approaches against those definitions.


People who claim absolute certainty about how all transmission happens are full of it & safely ignored. But as part of a layered "Swiss cheese" defence, cloth masks indoors almost certainly reduce R by a bit, which translates into a whole lot of avoided infections in places with widespread community transmission.


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## Docb (Jul 18, 2021)

Come back to my point.  Much of this sort of argument continues because nobody thinks about quantified risk.  So, all issues are either black or white. The probability of something happening is either 1 or zero.  The world just does not work like that except perhaps in the minds of PR merchants and PPE graduates from Oxford.

What I would like those involved in this debate to do is to provide estimates of the probability of getting infected under any given set of circumstances and how then demonstrate how that probability would be affected by the wearing of a mask. I would also like to know the level of error in those estimates.  That way I could make my own mind up and not have to listen to all the bull pooh being promulgated by the various factions in the powers that be trying to score points off each other.


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## Eddy Edson (Jul 18, 2021)

Docb said:


> Come back to my point.  Much of this sort of argument continues because nobody thinks about quantified risk.  So, all issues are either black or white. The probability of something happening is either 1 or zero.  The world just does not work like that except perhaps in the minds of PR merchants and PPE graduates from Oxford.
> 
> What I would like those involved in this debate to do is to provide estimates of the probability of getting infected under any given set of circumstances and how then demonstrate how that probability would be affected by the wearing of a mask. I would also like to know the level of error in those estimates.  That way I could make my own mind up and not have to listen to all the bull pooh being promulgated by the various factions in the powers that be trying to score points off each other.


There's some relevant data & references in the CDC guidance: https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/masking-science-sars-cov2.html


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## Docb (Jul 18, 2021)

Hi Eddy.  You have re-introduced the R number!  Back at the start it was the thing which told you all you needed to know about the pandemic.  It disappeared when it dawned on the classics graduates in charge that understanding what was going on could not be encapsulated into a single number.  You needed at think about at least two or three measures and the statistical errors associated with their estimates.  Far too technical for the poor dears.  Better to revert to point scoring debate.


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## Eddy Edson (Jul 18, 2021)

Docb said:


> Hi Eddy.  You have re-introduced the R number!  Back at the start it was the thing which told you all you needed to know about the pandemic.  It disappeared when it dawned on the classics graduates in charge that understanding what was going on could not be encapsulated into a single number.  You needed at think about at least two or three measures and the statistical errors associated with their estimates.  Far too technical for the poor dears.  Better to revert to point scoring debate.


I think R is pretty useful when you have widespread community spread and you don't have granularity on actual transmission chains. Anyway, all the epidemiologists I follow still reference it. 

BTW, don't be too hard on classics graduates. I did two years of classical Greek & being able to chant the first 20 lines of the Odyssey in the original makes me feel secretly _special_.


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## Docb (Jul 18, 2021)

Agree about the R number with the proviso that it needs to be used by people who know what they are doing.

Look at you in a new light, Eddy, with that revelation about the Odyssey.  I doubt whether any of the classics graduates in charge over here had anywhere enough talent to get that far!


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## Drummer (Jul 18, 2021)

I have been wearing a mask as it was required - logic had nothing to do with it.


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## pm133 (Jul 18, 2021)

Lucyr said:


> The issue of morality and potential confrontation is why i'll probably continue wearing my exemption lanyard



I'd be doing the same thing in your position.
It's a sad reflection of where we are in society at the moment that you would even need to consider doing this.
Hopefully over the next few months things will start to settle down.

I suspect we're going to see a rapid increase in cases for a while once all restrictions are removed and then hopefully it will settle down.
If we can then get through the winter without major issues and into next Spring without a major resurgence then I think we can start to properly put this behind us.


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## pm133 (Jul 18, 2021)

Amity Island said:


> I still can't believe they brought mask wearing in. Like you say, it's being indoors, breathing in shared air with infected people where the risk lies. I too have been saying this from the very beginning. When they brought the masks in last year, cases soared.
> 
> Now "they" are soon to be letting us breath again without masks. Something which should never have been taken away to begin with.
> 
> ...



That second sentence is the precise reason why covid waves keep hitting us despite obsessive mask-wearing. It's shared air in poorly ventilated areas.

Why has scientific reasoning been ignored?

Two reasons in my opinion.
Firstly, they don't trust Joe Public to observe social distancing without being reminded there's a pandemic around.

Secondly, the government scientific advisors are dominated by behavioural experts. The latest fad is this "nudge" theory nonsense. Good luck trying to change anyone's mind once they start believing things like this. There's this idea that you can manipulate people towards what you have in mind for them at low or zero cost. Masks absolutely serve that purpose - a visual reminder to socially distance. It's deeply insulting but most people don't know this is what is happening.

You also asked about the opposition? Everyone is in the same boat. They're all scared of being seen to make a mistake. Politically they have no better idea about how to overcome covid than the Tories. Same with the SNP in Scotland. Same with Labour in Wales and same with the coalition in Northern Ireland. No country has managed to get anywhere with covid. Each wave is bigger and longer than the last. Vaccines are, in my opinion, the only route out short of going for full herd immunity and taking the hit. No opposition is ever going to advocate that.


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## pm133 (Jul 18, 2021)

Amity Island said:


> Yes very important. It's been very devicive. We shouldn't be judging or assaulting others who prefer to breath naturally, as we were designed to do. Its incredibly worrying that those who we trust to be honest and truthful to be acting with integrity, to be acting in our best interest are doing anything but that.



People don't know how to debate AI. They don't get taught in school and so they learn only from the internet. This is something rich people are much better at. Because people don't know how to debate, they see every question about their views as a challenge to them personally. You're not defeating their argument, they see it as though you are crushing, demolishing, slam-dunking, annihilating etc. them personally. The view is that in arguments, people are not taking an oposite view to you, they are idiots, bigots, scum, filth. Rather than attacking the ideas, the person gets attacked. And so people get ultra-defensive. That then provokes a similar response and you then have polarisation over everything. You only need some of that to spill out from Facebook and Twitter into a pub at closing time amongst drunks and you have violence on your hands. During the Scottish Independence and the Brexit referenda, families actually broke up over this type of thing. Incredible really.

Politically, certainly in my lifetime, there's never been a period where the choice of available leader of the country was so poor.
Are we seriously supposed to believe that the best two people to choose from to run the UK out of 65 million people was either Boris Johnson or Jeremy Corbyn? I suspect there has never been a worse choice than that for Prime Minister.


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## pm133 (Jul 18, 2021)

Docb said:


> Come back to my point.  Much of this sort of argument continues because nobody thinks about quantified risk.  So, all issues are either black or white. The probability of something happening is either 1 or zero.  The world just does not work like that except perhaps in the minds of PR merchants and PPE graduates from Oxford.
> 
> What I would like those involved in this debate to do is to provide estimates of the probability of getting infected under any given set of circumstances and how then demonstrate how that probability would be affected by the wearing of a mask. I would also like to know the level of error in those estimates.  That way I could make my own mind up and not have to listen to all the bull pooh being promulgated by the various factions in the powers that be trying to score points off each other.



Ideally the side mandating a legal requirement for something would have provided this evidence to justify inconveniencing everyone but that didn't happen in this case.

Personally, I have to say that I'm only interested in giving my opinion, hearing others opinions and having a bit of to-and-fro discussion. I'm not in the game of trying to change others opinions, force my opinions on them or hold anything against them for having a different view.

Some of us have a background which enables us to make more informed judgements about masks than others but everyone else, in the absence of full information, should just make their best judgment and act accordingly. 

Best of luck to everyone in England tomorrow. Everyone else is watching with bated breath and crossed fingers to see how it goes.


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## Bruce Stephens (Jul 18, 2021)

pm133 said:


> I've been banging on about this for over a year now and it's nice to see someone in authority finally publicly saying it.


And a response from another SAGE expert:

__ https://twitter.com/i/web/status/1416810639339794435


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## everydayupsanddowns (Jul 18, 2021)

Interesting @Bruce Stephens

It certainly doesn’t seem to be a straightforward or easy question. And as that Trish Greenhalgh twitter thread explored, standard RCT models don’t really apply.

This graph of observational data from early on caught my eye though. Not necessarily causative. But certainly interesting.


__ https://twitter.com/i/web/status/1414294302314930178
By the time we eventually brought masks in, I suspect the horse had bolted and the graphs were already poised to soar.


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## BlueArmy (Jul 18, 2021)

According to this report only FFP3 face masks protected the staff 100% against covid - this level of filterstion is what you need when handlijg asbestos. Not sure what the tweet above from the professor is based on. If you want real protection for yourself from the virus - I’d buy a certified version of these and nothing else. My pack is on order.









						Covid: Masks upgrade cuts infection risk, research finds
					

Wearing a high grade FFP3 mask can almost entirely protect health workers from Covid, research finds.



					www.bbc.co.uk


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## Bruce Stephens (Jul 18, 2021)

BlueArmy said:


> According to this report only FFP3 face masks protected the staff 100% against covid - this level of filterstion is what you need when handlijg asbestos. Not sure what the tweet above from the professor is based on. If you want real protection for yourself from the virus - I’d buy a certified version of these and nothing else.


That's the opposite direction.

The question that's usually meant in this context is wearing face coverings in order to reduce transmission _from_ people wearing the face coverings. (That is, how much does it help if most people wear such inexpensive face coverings?)

But yes, what kind of mask is needed to protect the wearer is also important, so healthcare workers likely ought to be using FFP3 masks, and presumably people who are CEV ought to consider those more expensive masks as fewer other people may be wearing any kind of face covering.


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## Lanny (Jul 19, 2021)

From an asthma point of view, I’ve found wearing a mask EXTREMELY difficult! Since having had covid in May 2020 & long covid symptoms since then where my asthma is the worse it’s ever been since childhood, every time I’ve had to go out for medical appointments & walking long hospital/health centre corridors I’m left gasping for breath with the mask making it much harder to breathe afterwards when catching my breath back: have to hold the cloth up an inch off my mouth just so it doesn’t get sucked into my mouth as I’m gasping for air!

I’ve had both vaccines now & would prefer not to wear a mask on the few times I need to go out, medical appointments, as I will still probably not go out much despite the lifting of restrictions!


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## BlueArmy (Jul 19, 2021)

Bruce Stephens said:


> That's the opposite


I know Bruce - but today any protection we may have got from other people wearing masks is gone. Personally I’m moving to self preservation now, as the great British public will ditch masks today on mass.


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## Pine Marten (Jul 19, 2021)

Anecdotally - I went out this morning to the docs for my annual HbA1c blood test etc., and most people in the street who had masks were wearing them around their chins. I put mine on when I went into the surgery, the staff were wearing them (reception staff are behind a screen), the chairs were socially distanced in the waiting area and I was escorted to the 'way out' door at the end. 

At least the surgery is now open - when Mr Marten had to take a letter round the other week he had to ring the bell repeatedly to get someone to open the door.


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## Leadinglights (Jul 19, 2021)

We have just been out to a couple of shops and a guesstimate was 50:50 people wearing masks.
My O H had a hospital appointment last week and none of the hand sanitiser stations were working with signs on them to say so.


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## Eddy Edson (Jul 19, 2021)

Amity Island said:


> If masks work, then please share your evidence of their impact on case numbers.
> 
> Cases soared after 24th July 2020 when masks were made mandatory - see graph. To convince me otherwise, I'd like to see a series of graphs showing how cases plummeted after their introduction.
> 
> ...


You really can't look at one measure in isolation; it's the mix. And the devil is in the detail - eg compliance, exceptions. In Swiss Cheese terms, you have to cover all the holes - if one of your measures is deficient, the virus will get through.

For the UK last summer, I'd point to the lifting of international travel restrictions around that time. Most of the virus in the UK in later summer/autumn was apparently seeded by holiday makers returning from Spain then spreading through their households (according to the genomics).


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## rebrascora (Jul 19, 2021)

pm133 said:


> If you imagine that the covid soaked particle is the size of a basketball, that's like throwing the ball at a net which has holes the size of Belgium and expecting the ball to stick in the net. You really are going to catch virtually nothing. If anyone believes otherwise and wants to continue wearing a mask, they are very welcome to do so but the Physics is crystal clear on this. Also, it's not my place to tell you not to wear masks.



I wasn't going to get involved in this discussion but having read your last post about debate, I realize that it is important to voice your own opinion and challenge others when it doesn't appear to be entirely accurate or logical. I therefore decided that I would like to present my thoughts and particularly to challenge your analogy above about the basket ball and Belgian sized net.

Firstly, most nets are quite thin and usually thinner/finer than the object they are trying to catch. In the case of a mask, you are looking at something more akin to a wall made of tubes rather than a net. 
A multilayer mask means you have more than one wall of tubes, quite probably offset so there is much less chance of the particle negotiating several layers. I have no idea of the actual length those tubes might appear in relation to the particles it is trying to collect and I don't have time or inclination to work it out nor do I wish to make rash analogies about basket balls and or nets which would allow the country of Belgium to pass right through them, so I will leave it for the individual to work out or try to imagine. 

You then have to consider that you can throw a basket ball reasonably straight but many of these particles will be moving quite haphazardly so more likely to make contact with the surface area of those tubes where they will likely stick rather than bounce off or slide through, because the fabric is absorbent.

All of these things make the picture you describe very different to the way I imagine it and to me it suggests that many more of the particles will be captured by the mask than your analogy suggests, particularly the larger denser ones and they will carry the biggest virus load and therefore, when the amount of virus needed to infect someone is more substantial than a single particle, the mask has to have a positive impact in protecting others.....

That's my take on it anyway and I will be continuing to wear a mask in shops etc for the foreseeable future. I also agree that the mask is a visual reminder that we are not out of the woods and still need to take precautions and now that we all possess masks it is a minimal inconvenience to use them.


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## pm133 (Jul 19, 2021)

Bruce Stephens said:


> And a response from another SAGE expert:
> 
> __ https://twitter.com/i/web/status/1416810639339794435



Like I said above Bruce, you can either have the background to make your own informed decisions or you do your best to pick the scientist you want to believe in and move on accordingly.

What is at the heart of my decision on masks?

I already know about the relative sizes of pore holes in various masks.
I already know that covid is airborne using water particles as a vehicle. 
I already know that when you sneeze, breathe or cough, a massive range of particle sizes are emitted - not just droplets.
I already know that all sizes of water particles emitted during breathing, sneezing and coughing are bigger than the virus they carry.
I've known all of that for over a year and as far as I'm concerned those are indisputable facts with research to back them up.

Everything else flows from that.

How does covid know only to attach to droplets and not smaller particles? That makes no sense whatsoever.

How do you catch a basketball in a net with holes the size of Belgium? This in particular is the killer argument for me and I can't imagine that anyone is going to be able to easily punch a hole in it.

Responses such as "what harm can it do to wear masks" and "surely every little helps" and especially the flawed cheese slice model which every man and his dog has suddenly become a world-leading expert in, (the holes displayed in the cartoon are half a million times too small) are incredibly poor responses.

My conclusion is that masking up is pretty much useless but I respect others right to come to whatever other conclusion they want.


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## pm133 (Jul 19, 2021)

rebrascora said:


> I wasn't going to get involved in this discussion but having read your last post about debate, I realize that it is important to voice your own opinion and challenge others when it doesn't appear to be entirely accurate or logical. I therefore decided that I would like to present my thoughts and particularly to challenge your analogy above about the basket ball and Belgian sized net.
> 
> Firstly, most nets are quite thin and usually thinner/finer than the object they are trying to catch. In the case of a mask, you are looking at something more akin to a wall made of tubes rather than a net.
> A multilayer mask means you have more than one wall of tubes, quite probably offset so there is much less chance of the particle negotiating several layers. I have no idea of the actual length those tubes might appear in relation to the particles it is trying to collect and I don't have time or inclination to work it out nor do I wish to make rash analogies about basket balls and or nets which would allow the country of Belgium to pass right through them, so I will leave it for the individual to work out or try to imagine.
> ...



I can't stress this enough. I welcome any challenge to any point of view I might express. I'm quite happy to change my mind if you are persuasive and I never take offence. Unless I start getting called names of course.

I entirely understand about the real structure of fabric masks in real life.

I am using the basketball as a cartoon analogy in exactly the same way that others are using the cheese slice model because I'm not discussing this in a room full of research physicists or chemists. If I start talking about air pressure from breathing, pliable membranes, unstructured solids, cross-linking between polymeric substances, Graham's Law of Diffusion of gases through a solid, kinetics and non-linear fluid dynamics I'm going to lose pretty much everyone. That's my defence for using the basketball analogy.  It's not perfect, but show me a scientific model which is. We're still teaching school kids that electrons zoom around the atomic nucleus like planets around the sun despite 100 years of knowledge that they do no such thing. 

In addition to this I am also saying that the bulk of your breath goes out the sides of the masks anyway because they are not sealed so there's a couple of arguments there to explain why we have so much covid spread despite a year of mandatory mask wearing.

As for you personally continuing to wear a mask?
I fully support your right to do this without others having a go at you for doing so.
It's entirely within your rights and I would never judge you for it. I know you aren't asking for validation but we're living in a world where insults are flying everywhere on this so I just wanted to say it.

I'm interested in seeing what happens with the ordinary public at large over the next few weeks. I genuinely don't know whether they'll ditch them en masse or keep them. I swing from one opinion to the other.


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## rebrascora (Jul 19, 2021)

@pm133 
But your analogy hugely over simplifies the argument and makes it more binary and therefore polarizing. It is not at all like throwing a basketball at a net the size of Belgium. It is much more complex which is why many top scientists cannot agree on the subject. You have said nothing to make me change my mind and in fact, your basket ball analogy convinces me that your arguments and judgements are not to be trusted no matter how much you know about particle physics.


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## pm133 (Jul 19, 2021)

BlueArmy said:


> According to this report only FFP3 face masks protected the staff 100% against covid - this level of filterstion is what you need when handlijg asbestos. Not sure what the tweet above from the professor is based on. If you want real protection for yourself from the virus - I’d buy a certified version of these and nothing else. My pack is on order.
> 
> 
> 
> ...



As another poster said earlier, not everyone can wear masks for medical reasons.

I don't buy into the 100% protection thing as a general rule but there is clear evidence that they work better than surgical masks and they appear to protect the wearer.

It's not for me I have to say but those who can should absolutely be buying these.


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## pm133 (Jul 19, 2021)

rebrascora said:


> @pm133
> But your analogy hugely over simplifies the argument and makes it more binary and therefore polarizing. It is not at all like throwing a basketball at a net the size of Belgium. It is much more complex which is why many top scientists cannot agree on the subject. You have said nothing to make me change my mind and in fact, your basket ball analogy convinces me that your arguments and judgements are not to be trusted no matter how much you know about particle physics.



I'm not trying to change your mind or anybody else's.
I'm just giving my opinion as part of an exchange of ideas, taking on board alternative view points and having a look to see whether anything has changed my position.

I can't control how people feel about my posts and I can't control how they respond - that's on them.
I will say though that I really don't appreciate your last sentence about trust. In the context of any discussion this sort of thing isn't needed. You want to talk about polarising comments? That would be a good example.


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## pm133 (Jul 19, 2021)

Leadinglights said:


> We have just been out to a couple of shops and a guesstimate was 50:50 people wearing masks.
> My O H had a hospital appointment last week and none of the hand sanitiser stations were working with signs on them to say so.



Interesting to hear about mask wearing percentages since the law changed.

At my local hospital, pre-covid it was near on impossible to ever find soap in the toilets.
I used to bring my own.

And we wonder why hospitals are breeding grounds for disease.


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## pm133 (Jul 19, 2021)

Sigh! Yet another interesting thread is starting to get a bit too personal for my liking so I'm going to bail.

No wonder people stop posting.
At this rate we're going to have nobody left on here.


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## rebrascora (Jul 19, 2021)

Surely debate is all about winning people over to your argument or.... probably to a lesser degree, altering your own opinion. Trust is big part of that. If we say something which is clearly not true or inaccurate, then we lose credibility. That loss of credibility will mean that we have less trust in or respect for that person's opinion. 
However expressing that loss of trust has clearly upset you and I apologize for my lack of sensitivity in doing so.


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## Robin (Jul 19, 2021)

rebrascora said:


> Surely debate is all about winning people over to your argument or.... probably to a lesser degree, altering your own opinion. Trust is big part of that. If we say something which is clearly not true or inaccurate, then we lose credibility. That loss of credibility will mean that we have less trust in or respect for that person's opinion.
> However expressing that loss of trust has clearly upset you and I apologize for my lack of sensitivity in doing so.


Keir Starmer has come out in favour of masks. As he’s a barrister and well used to weighing up arguments for both sides, you’d like to think he’s done that in this instance, (and isn’t just saying it because he feels as the Opposition he’s got to oppose the Government stance!)








						Covid: Lifting all restrictions at once is reckless, says Sir Keir Starmer
					

Boris Johnson has urged caution as most legal rules on social contact are lifted in England.



					www.bbc.co.uk


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## pm133 (Jul 19, 2021)

rebrascora said:


> Surely debate is all about winning people over to your argument or.... probably to a lesser degree, altering your own opinion.



No not necesarily.
This isn't parliament.
It's a diabetes support forum and we're just discussing things outside our immediate health concerns.
It's an exchange of ideas. Some of which are varied in depth and breadth.

That has two benefits of which changing your mind is just one aspect.
The far more important benefit is geting two people with diametrically opposed ideas to understand where each other is coming from. Done without personal attacks and with respect, that doesn't cause polarisation, it leads people to an acceptance of others viewpoints. That is what I want when I discuss things with other people. If I'm not getting it I'm happy to find another tribe to talk to.

You bring up trust when you are talking about someone deliberately and wilfully spreading lies. It's not appropriate to be bringing that up in this discussion simply because you don't agree with my model or my reasoning. We simply disagree having put our points across respectfully and we move on.

I'm not upset. I'm just not interested in discussions which get personal.
Your apology is appreciated but I'm not sure you're really getting the point of what my issue with your comment was. I hope this post goes some way to explaining it and that we can move on without being pissed off with each other.


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## Eddy Edson (Jul 20, 2021)

Amity Island said:


> I think you can, when millions of people suddenly start doing something at the very same time that has never been done before. When so many people are doing the same thing at the same time, it's perfectly reasonable to expect some kind of effect (e.g change in case numbers), even just a flattening of case numbers, but when you see cases soaring after their implementation, that for me, is evidence enough that wearing masks has failed to do anything noticeable and worthy.
> 
> One can refer to scientific studies forever, but there is no substitute for actual real world hard evidence.
> 
> ...


A lot of that is an artifact of the very low testing rates in the UK in the early days.  Various modelling groups estimate that actual cases were 10X+ more than reported cases. So while It might look like there was an unprecedented increase in cases from late summer:



... actually the infection rate probably only got back up to the level of the early days after the stupid Christmas opening up, after the stupid late summer/autumn one. 

You can see that in deaths, a metric with its own issues but a better reflection of actual infection rates:


Even with new variants (eg Kent), stupid relaxations, feeble compliance enforcement etc it took until early this year for things to get worse than the early days. And then things started to improve after re-tightenings early in the year, even before widespread vaxing.

All consistent with masks being an effective part of a mix of NPI's for reducing infection rates. But UK govt NPI policy and execution have been so bad, in general, that any individual measure has been a bit like sticking a finger in a crumbling dyke.


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## Docb (Jul 20, 2021)

Much in what you say @Eddy Edson but I'm going to come back to my underlying thesis, that you can use the data to support whatever cause you want to promulgate.  For example, the death data is confounded by the changes in definition about what should or should not be included that have been made over the period of the pandemic. Some will say that the changes reinforced the data, others will claim it makes the data unusable.  Reality is that it changes some probabilities, with some being changed more than others. 

Understanding what can be gained from studying the data requires a comfort with the concept of uncertainty and the ability to work with statistics.  I've not seen anybody in the political arena who has shown any ability in this area.  Opinion based on political dogma has ruled and to me that is the greatest failing in the way this thing has been handled.


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## BlueArmy (Jul 20, 2021)

pm133 said:


> As another poster said earlier, not everyone can wear masks for medical reasons.
> 
> I don't buy into the 100% protection thing as a general rule but there is clear evidence that they work better than surgical masks and they appear to protect the wearer.
> 
> It's not for me I have to say but those who can should absolutely be buying these.


I agree, I don't tend to deal in absolutes, was just quoting the article itself. However, the finer level of filtration has to be better than wrapping your face in a old pair of pants which is what most people are doing. Incidentally, I got refused entry to a shop last week as I forgot my face mask as I was out having a run so pulled my t-shirt up to cover my mouth and nose knowing it provided as good a protection as what the others were wearing, and they wouldn't let me in. Not sure if it's because I looked like a sweaty bank robber or the person behind the till had a brain the size of an ants, likely the latter. Either way, this madness needs to end.

I agree, it's a comfort blanket which at best reduces the dispersion distance of a cough or sneeze. But if people were civilised and coughed or sneezed into their elbows or a tissue as you are supposed to anyway, it would be as effective as a face mask.


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## BlueArmy (Jul 20, 2021)

Robin said:


> Keir Starmer has come out in favour of masks. As he’s a barrister and well used to weighing up arguments for both sides, you’d like to think he’s done that in this instance, (and isn’t just saying it because he feels as the Opposition he’s got to oppose the Government stance!)
> 
> 
> 
> ...


I think it's just classic opposition politics - as in, say the opposite to the government. It's lame really - because he can't lose saying it. There is no way of telling if not wearing them has been a good thing or not really. Personally, I think the government has got the country to the position where it has offered every adult a jab, now it's a experiment to just let it rip and see what happens. Not a fan of this government, but I support this personally. Can't run and hide forever and its getting to the point where the cure is worse than the disease.


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## Eddy Edson (Jul 20, 2021)

Anyway, FWIW this evidence review study gets cited a lot in epidemiologist discussions I've followed: https://www.pnas.org/content/118/4/e2014564118


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## Eddy Edson (Jul 22, 2021)

Grist for the mill ... New study looking at the impact of a mandatory mask policy on Melbourne's outbreak last year: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0253510

(Recalling that Melbourne managed to get cases from a daily peak of ~700 down to a sustainable zero over the course of a couple of months.)

Conclusion: The study estimates the mask mandate, independently of other measures, reduced Reff from ~1.2 to ~0.9. In other words, to a level where the outbreak was diminishing.

Obviously, how convincing you find this _should_ depend on yr assessment of the quality of the methods, but _in fact_ will probably depend on yr priors 





_Background_​_Whilst evidence of use of face masks in reducing COVID-19 cases is increasing, the impact of mandatory use across a large population has been difficult to assess. Introduction of mandatory mask use on July 22, 2020 during a resurgence of COVID-19 in Melbourne, Australia created a situation that facilitated an assessment of the impact of the policy on the epidemic growth rate as its introduction occurred in the absence of other changes to restrictions._
_Methods and findings_​_Exponential epidemic growth or decay rates in daily COVID-19 diagnoses were estimated using a non-weighted linear regression of the natural logarithm of the daily cases against time, using a linear spline model with one knot (lspline package in R v 3.6.3). The model’s two linear segments pivot around the hinge day, on which the mask policy began to take effect, 8 days following the introduction of the policy. We used two forms of data to assess change in mask usage: images of people wearing masks in public places obtained from a major media outlet and population-based survey data. Potential confounding factors (including daily COVID-19 tests, number of COVID-19 cases among population subsets affected differentially by the mask policy–e.g., healthcare workers) were examined for their impact on the results. Daily cases fitted an exponential growth in the first log-linear segment (k = +0.042, s.e. = 0.007), and fitted an exponential decay in the second (k = -0.023, s.e. = 0.017) log-linear segment. Over a range of reported serial intervals for SARS-CoV-2 infection, these growth rates correspond to a 22–33% reduction in an effective reproduction ratio before and after mandatory mask use. Analysis of images of people in public spaces showed mask usage rose from approximately 43% to 97%. Analysis of survey data found that on the third day before policy introduction, 44% of participants reported “often” or “always” wearing a mask; on the fourth day after, 100% reported “always” doing so. No potentially confounding factors were associated with the observed change in growth rates._
_Conclusions_​_The mandatory mask use policy substantially increased public use of masks and was associated with a significant decline in new COVID-19 cases after introduction of the policy. This study strongly supports the use of masks for controlling epidemics in the broader community._
​


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## everydayupsanddowns (Jul 22, 2021)

pm133 said:


> That's my defence for using the basketball analogy.  It's not perfect, but show me a scientific model which is.



For me the analogy treads a tricky line between clear comedy exaggeration, and functional illustration.

I confess I found it so unlikely that I spent a minute or two with the “500,000 times bigger”, and working out the diameter of a basketball to quickly discover that it was nothing like as big as Belgium.

Plus the 500,000 relies on the size of the virus particle itself, and this (as we all agree) is not uniformly how the virus will emerge.

The virus particle (or multiple particles) will be attached to droplets of widely varying sizes.

And from a carefully cnstructed n=1 experiment I have demonstrated to my own satisfaction that some air (doubtless containing small particles) passes through the layers of the masks I wear, but that quite a lot of water vapour is captured.

And so, in just the same way as I recognise that my recycling efforts are not going to entirely solve the global warming planet crisis single handed, I am happy to make a small contribution by doing something rather than nothing.


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## Docb (Jul 22, 2021)

Eddy Edson said:


> Grist for the mill ... New study looking at the impact of a mandatory mask policy on Melbourne's outbreak last year: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0253510
> 
> (Recalling that Melbourne managed to get cases from a daily peak of ~700 down to a sustainable zero over the course of a couple of months.)
> 
> ...


I wonder how they came up with the "hinge" date.  I also wonder what the effect of shifting it a few days either side of the 8 days might be.  Also, never really did get my brain round the idea of linear regression of a logarithmic relationship.


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## Bruce Stephens (Jul 22, 2021)

Docb said:


> Also, never really did get my brain round the idea of linear regression of a logarithmic relationship.


That's simple enough, isn't it? Something that's exponential becomes linear when you take logs so a sensible thing to do in this case is to use linear regression on logs of your exponentially changing thing.


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## Eddy Edson (Jul 22, 2021)

Bruce Stephens said:


> That's simple enough, isn't it? Something that's exponential becomes linear when you take logs so a sensible thing to do in this case is to use linear regression on logs of your exponentially changing thing.


Like Bruce, I don't see anything very suspect with that part of it. On the hinge day: the paper says the SI includes a sensitivity analysis (which I haven't delved into).  

My immediate question on the methods was the use of archive photos from The Age newspaper to estimate mask compliance.  Again, I haven't delved into it, but I'd want to know more about how robust that is.


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## Docb (Jul 22, 2021)

I'm sure that my inabilities with respect to interpreting linear regression of logarithmic data has more to do with my brain than the method. 

It would be nice to know how the hinge day was chosen and whether any sensitivity analysis was done.  One thing for sure is that if I wanted to demonstrate an effect of masks, then I would have invented the idea and then put it exactly where it appears on the chart.

By the way, I am taking no side in the mask/no mask debate.  Just trying to illustrate the point I keep trying to make, that things are rarely as clear cut as some would make out.


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## Bruce Stephens (Jul 22, 2021)

Docb said:


> It would be nice to know how the hinge day was chosen and whether any sensitivity analysis was done.


It's in the paper.
The hinge day was estimated to be 8 days following the introduction of masks, based on a previous report observing an 8 day delay from the introduction of Stage 3 restrictions in Melbourne and a change in the epidemic growth rate [28], biological plausibility (a mean generation interval estimated at 4–6 days [29, 30], combined with delays in test-seeking and reporting), and assessment of model robustness, with sensitivity analyses used to explore alternate assumptions (S1 File).​


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## Docb (Jul 22, 2021)

Thanks Bruce, so as I thought it was an educated guess. As good a way as any of signalling the time you might expect to have an effect but not as clear cut as the analysis might suggest.  Eyeballing the data might suggest that 6 August could be equally as good a guess - that seems to be where there is a break in slope - and if that were taken then the conclusions may well be quite different.


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## Bruce Stephens (Jul 22, 2021)

Docb said:


> Thanks Bruce, so as I thought it was an educated guess. As good a way as any of signalling the time you might expect to have an effect but not as clear cut as the analysis might suggest. Eyeballing the data might suggest that 6 August could be equally as good a guess


Well, 6 August would be 16 days after the rule change, which feels like it's not quite as plausible as 8 days. But maybe they could produce support for 16 days, too. If you went there you might also have to have an argument about the influence (or lack of it) of this curfew (from 3 August), especially since you'd probably want to include some later data (otherwise the graph stops just 4 days later).

Nevertheless, it looks to me like pretty good evidence (on its own) that the introduction of mask probably had a positive influence. Not a massive one, but significant. Which matches the Sage estimates from last year, I think.


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## Bruce Stephens (Jul 22, 2021)

Amity Island said:


> For me, the graph indicates that cases started falling and levelling off the day immediately _after_ a the curfew was announced (30th July) which is the same date they used for their "hinge" day.


I think they'd argue that that's not plausible. You won't see the impact of a measure immediately: it'll take about a week, minimum.


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## Eddy Edson (Jul 22, 2021)

Bruce Stephens said:


> Well, 6 August would be 16 days after the rule change, which feels like it's not quite as plausible as 8 days. But maybe they could produce support for 16 days, too. If you went there you might also have to have an argument about the influence (or lack of it) of this curfew (from 3 August), especially since you'd probably want to include some later data (otherwise the graph stops just 4 days later).
> 
> Nevertheless, it looks to me like pretty good evidence (on its own) that the introduction of mask probably had a positive influence. Not a massive one, but significant. Which matches the Sage estimates from last year, I think.


Below is the sensitivity analysis from the SI. The "Estimate" column is the model's estimated change in daily growth rate attributable to the mask mandate for different hinge days.  Pulling the delay back to 6 days from 8 days means the change goes from -0.065 to -0.052, etc. Still pretty significant & enough to get Reff below 1. 

FWIW, the guy who was deputy Victorian CHO at the time said the other day that the mask mandate was the big swing factor in getting things under control, reflecting what seems to be the general opinion amongst the public health people.

*Table S1. Sensitivity analysis for hinge day in the linear spline model. *Estimate for the change in slope parameter for models that assume different transition dates


*Day mask impact observed **Estimate**Std. Error**t value**Pr(>|t|) **Adjusted R2 for overall model*29-Jul​-0.052​0.021​-2.619​0.014​0.530​30-Jul​-0.060​0.021​-2.863​0.008​0.547​*31-Jul*​*-0.065*​*0.022*​*-2.953*​*0.006*​*0.554*​1-Aug​-0.070​0.024​-2.964​0.007​0.552​2-Aug​-0.080​0.0264​-2.744​0.010​0.558​


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## everydayupsanddowns (Jul 23, 2021)

I think by now most of us probably have a pretty established view as to whether masks are acceptable to us personally, the level of discomfort they give us (mentally and physically), and whether they seem to be worthwhile as a precaution or not. And any time we see data or opinions about mask wearing and the effectiveness, or lack thereof, I think it’s inevitable that we will view those data through the lens of our existing opinion. Confirmation bias is a powerful thing.

For me, I think there is enough chance (not certainty) that they offer sufficient marginal benefit to overall transmission rates, that I am happy to accept the extremely minor inconvenience of a 2-4ply face covering when in a shop, and will continue to wear one while case rates are so high (they have never been higher where I live).


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## Docb (Jul 23, 2021)

Eddy Edson said:


> Below is the sensitivity analysis from the SI. The "Estimate" column is the model's estimated change in daily growth rate attributable to the mask mandate for different hinge days.  Pulling the delay back to 6 days from 8 days means the change goes from -0.065 to -0.052, etc. Still pretty significant & enough to get Reff below 1.
> 
> FWIW, the guy who was deputy Victorian CHO at the time said the other day that the mask mandate was the big swing factor in getting things under control, reflecting what seems to be the general opinion amongst the public health people.
> 
> ...



Can't help but think that if you were presented with the set of spots on the chart without all the lines and breaks and annotations, and told it was the log of a parameter vs time, you would be very brave if you suggested that something significant happened around 6 August.  

Again not saying that the interpretation is incorrect or that the CHO is mistaken, if he is good at his job then his judgement is probably the best indicator available.  Just my usual thought that there is a lot of presenting data to fit a political position going on at the moment and one should be a bit wary of it.

I'm with @everydayupsanddowns.  Wearing a mask is likely to have marginal benefit in some situations.  I can make my own guesses about when it would be sensible to wear one but it would be good if people stopped trying to prove points and analysed the problem in an open manner.  You may come to a conclusion that you cannot get definitive data and you might as well go on your gut reaction.  I have no problem with that, some things cannot be resolved.  The danger is in pretending that they can be.


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## Eddy Edson (Jul 23, 2021)

Docb said:


> Can't help but think that if you were presented with the set of spots on the chart without all the lines and breaks and annotations, and told it was the log of a parameter vs time, you would be very brave if you suggested that something significant happened around 6 August.
> 
> Again not saying that the interpretation is incorrect or that the CHO is mistaken, if he is good at his job then his judgement is probably the best indicator available.  Just my usual thought that there is a lot of presenting data to fit a political position going on at the moment and one should be a bit wary of it.
> 
> I'm with @everydayupsanddowns.  Wearing a mask is likely to have marginal benefit in some situations.  I can make my own guesses about when it would be sensible to wear one but it would be good if people stopped trying to prove points and analysed the problem in an open manner.  You may come to a conclusion that you cannot get definitive data and you might as well go on your gut reaction.  I have no problem with that, some things cannot be resolved.  The danger is in pretending that they can be.


Anyway, you asked what the effect in the model of changing the hinge date by a few days would be, and I provided the answer. Apols if that's not what you were actually looking for.

Of course, there's nothing particularly scientific about yr "marginal effect in some situations" judgement. As always, you can continue to hold on to unexamined priors, or you can engage with the science to try to improve them.


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## Eddy Edson (Jul 23, 2021)

Amity Island said:


> With such small overall cases numbers e.g around 400, a reduction in testing could quite easily be responsible for a drop in case numbers around the hinge date.


No idea where you're getting that from, but there was no particular reduction in testing, which was mainly widespread community testing, with hospital etc in-patients being a negligible proportion. Also, if you actually read the paper, you'll see that they address testing rates as a possible confounder:

_Including daily tests and the mobility index as additional covariates in the multivariate linear regression made little difference to the estimated growth rates and neither the coefficient for mobility (-0.034, p = 0.28) nor tests (6 x 10−6, p = 0.36) were significantly different to zero (S1 File)._

BTW, I don't really mean to mount a huge defence of the conclusions of this study. I really don't know enough about the statistical methods to do that & I'm waiting to see how it stands up to review and critique from experts.  But it's a big piece of work and it deserves more than people just waving their priors at it.


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## everydayupsanddowns (Jul 23, 2021)

Eddy Edson said:


> But it's a big piece of work and it deserves more than people just waving their priors at it.



I don’t disagree at all. And I hope papers and research work like this can continue to clarify the situation, and improve our response to what happens in the future (it feels like we’re gonna need it).

Pragmatically, like many complex situations where there are differences of opinion among scientists, specialists and the great unwashed alike, this is one of those questions where I have (for my own personal sanity) decided to dodge the need to pour endless time and effort into balancing the emerging claim and counter claim. I don’t lose anything by wearing, and there is some evidence to suggest that my wearing might be helpful in reducing spread. So if that’s wrong, and they actially offer no benefit, I’ve not lost anything. But if there is benefit then society will have gained.

I hope that in the end someone will coalesce the available data into some uber meta analysis that settles the question, but I don’t need that to happen for me to continue for the time being.


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## Docb (Jul 23, 2021)

Eddy Edson said:


> Anyway, you asked what the effect in the model of changing the hinge date by a few days would be, and I provided the answer. Apols if that's not what you were actually looking for.
> 
> Of course, there's nothing particularly scientific about yr "marginal effect in some situations" judgement. As always, you can continue to hold on to unexamined priors, or you can engage with the science to try to improve them.


Yes I did and was too busy thinking about the graph to thank you for doing it!  Still think that if you put your thumb over the last two data points, you would be hard pressed to say that the rest of the data did not come from the same population - unless you were trying to prove a point.

Totally agree that there is nothing particularly scientific about my judgement by I'm the only person who has to live with it. Dunno what I would say if others would have to rely on and work with what I said.


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