No significant effect of lockdowns on Covid-19 spread.
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PeterNSteinmetz
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So now you are just speculating and attributing malign motive to some of the leading researchers in the field. Oh dear.
dmspilot
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Except you are being deliberately misleading again in your choice of thread title, because this study isn't comparing lockdowns versus no lockdowns, but mandatory lockdowns vs voluntary interventions in Sweden and testing, contract tracing, and isolation in South Korea. This is not a study comparing lockdowns to doing nothing.
David Megginson
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I suspect we're on the same side in this question. New Zealand stayed open and didn't have a major outbreak, so people might naively look for a correlation there, but they'd be putting the cart before the horse — nobody does a shutdown until they're in imminent risk of a major outbreak, so if you're not staring an outbreak in the face, you don't do a shutdown.
PeterNSteinmetz
Ejection Handle Pulled
Please note, “not being discussed” and “data are being lumped in” are different than your statement of not being reported.
I do see the source of some ambiguity here though. I agree that “lumped in” is not quite the correct description.
I think the overall point is that it appears the total ILI situation, including both Covid-19 and other flus, appears to be the same as a bad normal flu season. It is not as though Covid has come along and stacked on top of the normal flu, rather it appears it has largely displaced it.
Frankly, the extent of this surprises me.
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PeterNSteinmetz
Ejection Handle Pulled
That is of course an ad hominem attack because you are attributing motive to me. This will be my last comment in this thread on title choice and I will not be revising it. You choose to interpret it a particular way, so be it.
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dmspilot
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That's the second or maybe third time you've accused me of being a lawyer. How is that not an ad hominem you've just made yourself?
As far as identifying your motive, it fits your pattern of behavior. Deductive reasoning.
PeterNSteinmetz
Ejection Handle Pulled
Anecdotal of course. And the overall scientific evidence on the source effect of cloth masks is quite mixed. The results of the DANMASK study, while not directly addressing source effect do not argue in its favor. And as noted above by David Megginson, the in-vitro studies strongly suggest a cloth mask is even less effective than the surgical masks used in the DANMASK study.
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PeterNSteinmetz
Ejection Handle Pulled
Let me offer the following as perhaps a synthesis regarding the original subject here, namely the effect of coercive lockdowns, as well as social distancing, voluntary measures.
It can simultaneously be the case that
1. Staying away from infected people will seriously reduce your chances of being infected by Covid-19.
2. That people will, at least for a period of time, choose to isolate themselves when such a pandemic is occurring.
3. That in the long run the virus will spread until heard immunity is reached, either through natural infection or vaccines.
4. That coercive lockdowns orders don’t significantly slow the spread in most western nations due to a combination of factors such as people traveling and socializing despite such orders.
Nothing inherently contradictory in all 4 of those given the complexity of the biology of viral illnesses and human behavior. And it strikes me that the data suggest all 4 of these are likely true.
It can simultaneously be the case that
1. Staying away from infected people will seriously reduce your chances of being infected by Covid-19.
2. That people will, at least for a period of time, choose to isolate themselves when such a pandemic is occurring.
3. That in the long run the virus will spread until heard immunity is reached, either through natural infection or vaccines.
4. That coercive lockdowns orders don’t significantly slow the spread in most western nations due to a combination of factors such as people traveling and socializing despite such orders.
Nothing inherently contradictory in all 4 of those given the complexity of the biology of viral illnesses and human behavior. And it strikes me that the data suggest all 4 of these are likely true.
dmspilot
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The DANMASK study does not argue in favor of source effect since it didn't address it, neither directly or indirectly. What you wrote above is called doubletalk.
PaulS
Touchdown! Greaser!
Anecdotally of course, my take on the spread of this virus is that there seems to be a lot of cases where someone is in an area of other people one day, then tests positive the next day, after the spread has already occurred. A friend was telling me about a co-worker yesterday, who was in an office, with everyone masked up. Another worker was there, with a dry sounding cough. The guy said he thought it was allergies, so went to work. The next day, he was tested and it came back positive. I maintain this guy must have not been feeling well, but made the decision to risk everyone else in his office because he wasn't sure if he was sick.
I think this happens often, people need to change their attitude toward illness and have more regard about protecting others from a sickness you may have. I've always been against "perfect attendance" awards, if you are sick stay home. When I had people working for me and someone would come in obviously sick, I would ask why they didn't take a sick day, 4 times out of 5 I would get the answer "those are for vacation, I can be sick here." Two seconds later they'd be on they're way home.
I think masks help a little, but aren't that effective.
I think this happens often, people need to change their attitude toward illness and have more regard about protecting others from a sickness you may have. I've always been against "perfect attendance" awards, if you are sick stay home. When I had people working for me and someone would come in obviously sick, I would ask why they didn't take a sick day, 4 times out of 5 I would get the answer "those are for vacation, I can be sick here." Two seconds later they'd be on they're way home.
I think masks help a little, but aren't that effective.
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jsstevens
Help yourself. It’s sooo true.
I'm curious as to what those social costs are, and what the mechanisms are that cause them to far outweigh the benefits.
PeterNSteinmetz
Ejection Handle Pulled
Well, let’s consider that scientific question of what the DANMASK study implies in terms of the source effect. It does not directly address that question, as noted by the authors, but I think does argue indirectly against it.
If a source effect is true, it must be because the mask of the wearer is reducing the total number of virions to which the recipient is exposed, thereby reducing the likelihood of infection.
If there is such a reduction, is it likely that it is only one way? If it is of equal strength both ways, then such an effect should benefit the wearer as well. What the DANMASK study showed is that there is no such significant effect for the wearer of surgical masks, at least as measured when making a recommendation to wear the masks and it was self-reported they were worn.
We also know from the in-vitro studies that the cloth masks are considerably less effective than the surgical masks at impeding the number of droplets expelled.
So for there to be a significant source effect given the results of the DANMASK study it would need to be the case that there is effectively a strong asymmetry for the protective effect for the wearer and the recipient. While that is possible, I don’t think one can argue that the results of the DANMASK study argue in favor of a source effect. Do you? If so, how do those results in particular support the existence of a source effect?
I would put the DANMASK study in the indirect evidence against the source effect hypothesis (not strong direct evidence). Thus I said they do not support such an effect. Sadly we don’t have much good data regarding the source effect.
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dmspilot
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That is actually not true. The DANMASK study showed there was not a 50% reduction in infection rates among mask wearers. The study was inconclusive regarding protective effect below 50%. Your extrapolation of the data to try to argue against source control is mere speculation.
So you are saying a cloth mask wouldn't stop the majority of what is coming out of the guy's mouth below? I'd hate to be in front of him.
denverpilot
Tied Down
Covid or anything else, there’s a misplaced hope. Government operates with its own best interests in mind, always.
Just sayin’.
Even being slightly less cynical, it always operates against some large number of people’s interests at all times. Sometimes for good reasons, often for “tradition” or popularity like the prom King and Queen in high school.
It’s really not (objectively) a hope anyone sane holds on to much after about age 12.
PeterNSteinmetz
Ejection Handle Pulled
Let's look at the study itself (available at https://www.acpjournals.org/doi/full/10.7326/M20-6817). There has been a great deal of mis-reporting in the media.
It reported NO significant effect (p<0.05) on the likelihood of infection due to the recommendation to wear a mask and self-reported wearing. The confidence interval for a possible effect ranged from 46% reduction to a 23% increase in the rate of infection. It had an 80% power to detect a 50% reduction and failed to detect that.
What this means in more lay terms is that that there was a 95% chance that any observed differences in the rates of infection were due to chance. However, on the off chance the intervention had some effect, the best estimate would be a 15% reduction, but there is a 95% chance the true effect lay somewhere between a 46% reduction and a 23% increase.
Agreed, we need to be cautious about interpreting null results such as that obtained in the DANMASK study (Edited post above to reflect that I was speaking of statistically significant effects). Agreed, any inference regarding source effect from the DANMASK study is weaker. But I don't think the results of the DANMASK study can be said to argue for a source effect at all.
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PeterNSteinmetz
Ejection Handle Pulled
Me too. I am not saying that at all. WRT to mask wearing, I am saying that I think the evidence that the general public wearing cloth mask will slow the spread of COVID-19 is at best mixed. And that the evidence that coercive mask mandates will slow the spread of Covid-19 is even weaker.
And that guy should be coughing or sneazing into his sleeve or a kerchief if he wants to keep his mask clean. Why even wear one like that?
PaulS
Touchdown! Greaser!
So you are saying a cloth mask wouldn't stop the majority of what is coming out of the guy's mouth below? I'd hate to be in front of him.
He looks like he is well hydrated.
One physician's reasoning on the mask issue:So you are saying a cloth mask wouldn't stop the majority of what is coming out of the guy's mouth below? I'd hate to be in front of him.
https://larsonsportsortho.com/are-masks-effective-against-the-coronavirus-disease/
He also did the following demo. It's not quantitative, but it does suggest that even home-made masks redirect the exhaled airflow, which could help make physical distancing more effective.
Face Mask Demo Using Cigar Smoke
[Edit: Corrected second link.]
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Unfortunately, there are many people like the guy below. I'm not even sure he is sneezing. If he were talking to me, I'd want him to wear his mask. You follow your own choice.
PeterNSteinmetz
Ejection Handle Pulled
In terms of my own choices. I try not to be in crowds like that at all. High risk situation. If I must be in something like that, I wear an N95 and don't depend on others to exercise good sense. I also try to distance more from people behaving like that.
For the record, if people or businesses (not in mandated areas) ask me to wear a mask, I do so as a courtesy to them.
Masks are inexpensive, and without going into detail, there is a very long list of coercive mandates that have far greater costs and other consequences, so I've never understood why there is so much resistance to this one.
dmspilot
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The repetitive insinuations that I haven't read the study are getting old. More ad hominem from you.
Tarheelpilot
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Tarheelpilot
Me too. When I asked it was vague and general reference to it being lots of little things that swayed the group. Anyway. I can’t answer the question, unfortunately.
denverpilot
Tied Down
Probably not the masking, but the forced closure of businesses is the real social balance issue.
My financial guy said this week roughly 1/3 of the country is teetering on the edge of bankruptcy. The other 2/3 is doing quite well.
In big round numbers that’s affecting 33% of the populace to protect against something killing 1%.
And the 1% continues to hold solid everywhere without much significant change off of that number statistically, no matter what any particular area did to stop it.
It’s a foot race between vaccination and catching it that’s going to take another year-ish in big round numbers. With perhaps ironically or just interestingly, both accelerating. Virus mutating to faster infection rates, and hopefully drug makers adding lots and lots of manufacturing capacity.
Still headed for 3.2M dead in the US unless the official infection rates are wildly off. Need about a 4X difference in reported values vs reality to really notice much of a difference in timeline — many months of change toward “sooner” on that linear graph.
If numbers are accurate (doubtful for numerous objective reasons) we’re just over 10% on the overall timeline. Thing hasn’t even gotten rolling yet. Maybe 20%.
The debates about accuracy will continue for a decade. Or more. People still debate 1918.
Someone will get a good chuckle out of threads like this one on archive.org or similar in a couple decades.
“Aww, look at what they didn’t know...” just like we get a chuckle out of old newspapers from back then.
NYC has hit “peak meme”, according to Louis. Pretty funny. The special “outdoor/indoor” dining. Just trying to survive.
My question was about masking. I agree that the consequences of business restrictions are very large.
Deelee
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denverpilot
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Fair enough. I see a lot of people equating masking to the bigger picture business problems.
A common mistake of switching symbolism for mathematical reality IMHO.
PeterNSteinmetz
Ejection Handle Pulled
I agree that sadly there is such a very long list of coercive mandates with far greater costs and other consequences.
In terms of the resistance to this, I can only speak speculatively on why there has been as much resistance as there has been generally. But here are my speculations. I think the reasons likely fall into 3 categories:
1. Discomfort. Let's face it, the more effective the mask is, the less comfortable wear. Example: wear a P100 versus a single layer cloth mask. People do find these things uncomfortable and annoying, for a variety of reasons. If the possible benefits have mixed evidence and the potential harm to other people is very indirect, I can sympathize with why people resist wearing them.
2. Potential medical harm. There is some evidence, for example MacIntyre et al. 2015, that cloth mask wearing could increase the likelihood of respiratory infections overall. Not convincing evidence in my opinion, but some. And this does agree with people's feelings that restricting ones breathing is not a good thing. Also there is fairly good evidence that they can cause allergic reactions in susceptible individuals.
3. Political. Obviously won't go into detail on this, but I think a fair number of people feel that it is wrong for the government to coerce them in the presence of this type of mixed evidence. And of course this agrees with the feeling of a fair number of US citizens that they just don't like the government telling them what to do.
I really have no idea how these three categories would rank in terms of importance for the majority of people who resist mask wearing.
PeterNSteinmetz
Ejection Handle Pulled
I am curious where you got the 3.2M dead?
My own rough guestimate (as you note, very inaccurate on all of this right now) would go as follows:
Estimates of R0 suggest a herd immunity fraction of about 65%. IFR appears to be on the order of 0.25% (or maybe lower with improved treatments, but that is sort of middle of the range).
So 330M people x 0.65 x 0.25% = 536,250.
Obviously back of the envelope calculation and maybe something more sophisticated predicts higher? (Or maybe that is 1% of the 330M?)
dmspilot
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Stop trying to debate me via PM. It is not appreciated.
PeterNSteinmetz
Ejection Handle Pulled
This statement is not fully correct and could mislead readers into thinking the DANMASK study says nothing about the protective effect or lack thereof below a 50% reduction. That is incorrect.
If one is going to interpret this study which failed to show a significant level of protection for the wearer, it is best to stick to the best estimator, which is a 15% reduction, and a possible range from a 46% reduction to a 23% increase in the likelihood of infection.
Based on that confidence interval, one can compute that overall likelihood that the surgical mask wearing group had an actual INCREASE of infection, not a decrease. That likelihood is close to about 25%. Not an insignificant chance that the wearing of the surigcal masks actually did harm.
Of course, it was a null result. So there is a 95% chance that any such observations were due to chance alone.
PeterNSteinmetz
Ejection Handle Pulled
Here is another way to think about the possibility of a source effect. What sort of experiments would demonstrate there is not a source effect, at least in principle?
The authors of the last recent review I had posted basically stated they weren't sure that one could be performed. Certainly such an experiment can be conceived in principle, so the source effect hypothesis is not literally a non-falsifiable hypothesis in the logical sense. But it is rather close if no such experiment can practically be performed.
So I ask supporters of the source effect hypothesis, what sort of data would persuade you that there is no source effect? If one has a belief for which there is no possible data in principle which would refute it, then one has a non-falsifiable belief. Further discussion is pointless.
The authors of the last recent review I had posted basically stated they weren't sure that one could be performed. Certainly such an experiment can be conceived in principle, so the source effect hypothesis is not literally a non-falsifiable hypothesis in the logical sense. But it is rather close if no such experiment can practically be performed.
So I ask supporters of the source effect hypothesis, what sort of data would persuade you that there is no source effect? If one has a belief for which there is no possible data in principle which would refute it, then one has a non-falsifiable belief. Further discussion is pointless.
PeterNSteinmetz
Ejection Handle Pulled
Hey, was just trying to politely give you a chance privately to remove your numerous posts which violate the TOS.
(To the moderators, I will remove this once his violating post quoted is removed.)
You can control who can write messages on your profile page or start a "conversation" with you. Select the little person icon near the top-right corner of the page, and select "Privacy." Go to the "People Who May..." section and set "Post messages on your profile page" and "Start conversations with you" to "People You Follow Only." (You can add people to your follow list by opening the "People You Follow" link on the left-hand side of the same page.)
Matthew Rogers
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Matt R
Source of the charts with data directly from CDC.
https://www.cdc.gov/flu/weekly/index.htm
3. Hong Kong - a country that already wore masks before 2020, experienced prior pandemic viruses (SARS), and provides highly effective masks to all citizens. They were already very far along in combating the spread as 75% wore masks by January 23, 2020 and at 99% mask wearing compliance by 21 days of virus detection in the country.
https://www.bmj.com/content/369/bmj.m1880
The Hong Kong government has begun to distribute reusable face masks to all residents, as part of its strategy to protect the city’s 7.5 million people from covid-19.1 In addition, all households will be supplied with 10 single use surgical masks, 30 million in total, in late June.
The CuMask+ was developed by the Hong Kong Research Institute of Textiles and Apparel and is manufactured locally and in Vietnam. It has six layers, two infused with copper, which is capable of immobilising bacteria, common viruses, and other harmful substances. The name refers to the chemical symbol for copper and is a play on the words “see you.”2
On the first day of online registration for the mask, there were 2 million registrants.3 Primary school and kindergarten children will each receive two child sized masks when schools resume and masks will also be distributed to residential homes and social welfare agencies.
Since 23 January when the first cases of covid-19 were confirmed, Hong Kong has been relatively successful in containing the epidemic. Despite the city’s proximity to mainland China and its extreme population density, as of 6 May there have been only four deaths and 1044 confirmed cases, and no locally acquired cases for 18 consecutive days. This has been attributed to a combination of border control and social distancing measures, aggressive testing, contact tracing, and mandatory quarantine, and the early and widespread adoption of personal protective behaviours by the population.4
Even before the government began to introduce measures to combat the disease, wearing a surgical mask became an almost ubiquitous practice in Hong Kong as soon as news of a SARS like outbreak across the border in China reached the city in early January.5 Surveys of the population found that by 23 January, 74.5% of respondents wore face masks in public, and the figure was up to 99% within three weeks of the outbreak starting.67
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