9 ms·

Correlation Between Mask Compliance and Covid-19 Outcomes in Europe

75 points by shaicoleman 4y ago

deleted 4y ago
[deleted]
mhitza 4y ago
Conclusions > While no cause-effect conclusions could be inferred from this observational analysis, the lack of negative correlations between mask usage and COVID-19 cases and deaths suggest that the widespread use of masks at a time when an effective intervention was most needed, i.e., during the strong 2020-2021 autumn-winter peak, was not able to reduce COVID-19 transmission. Moreover, the moderate positive correlation between mask usage and deaths in Western Europe also suggests that the universal use of masks may have had harmful unintended consequences.
- adamredwoods 4y ago
  Dangerous conclusions, attempting to convince people that wearing masks is harmful. So many assumptions are made that this 'correlation' gives little insight. For example, place of case infection is not even considered. If most people become infected at gatherings where their mask is left off, but they wear their mask in public, then how is this factored? Or perhaps those who wore masks more frequently were at greater risk of infection? I've been to the hospital recently, and have witnessed the extreme use of masks there. They would laugh at this article.
maneesh 4y ago
The one sentence summary: “These findings indicate that countries with high levels of mask compliance did not perform better than those with low mask usage.“ Should this source be trusted or not? If it’s trusted, does that mean that our efforts to mask were basically a waste of time, or not?
- hannob 4y ago
  1. It's a publication with post-publication peer review. Meaning: It's not been peer reviewed before publication. That's not invalidating its findings, but it's evidence one should rate as potentially of lower quality until other experts have reviewed it. 2. You should never look at one study, but at all the evidence. It is generally difficult to study the effects of something like mask wearing, as you can't easily do something like an RCT (or if you try it may not tell you what you wanted to learn, i.e. it's even harder to test if others are protected by mask wearing). There are no easy answers, but it's been my impression that experts reviewing all the evidence in the past came to the conclusion that mask wearing likely works quite well.
  - elcritch 4y ago
    A single study generally isn't conclusive, especially in a field with as many confounding factors as public health policies. It'll take a lot of time and hard work to decisively say if there's an effect and to what degree. The various studies and meta-analysis I've read appear to indicate that masks somewhat slowed the transmission rate, but overall didn't greatly reduce final case counts. There's enough uncertainty that I believe we'll need solid RCTs to get better answers. There was on large RCT slated to happen in west African country (Rwanda maybe?) where covid-19 hadn't hit.
- systoll 4y ago
  > Should this source be trusted or not? Seems legitimate, though that doesn’t mean it’s a particularly valuable analysis. > If it’s trusted, does that mean that our efforts to mask were basically a waste of time, or not? It doesn't say. In a world where everyone wakes up each day, checks the daily cases nearby, and only puts on a mask if it’s over 1000… you'd get near perfect correlation between mask use & covid cases, even if the masks prevent every single transmission. And that’s not all that out of line with reality. High rates of Covid absolutely cause increased levels of mask compliance, so seeing a correlation between the two doesn't really tell us much about mask effectiveness. You could maybe do some time-series analysis to try and get a better idea. The decision to mask today would be influenced by cases in the recent past, and any actual effect of mask wearing would only affect diagnoses 3-5 days later. But I’ve not done that math, and neither has this paper.
mnw21cam 4y ago
While this is a very interesting study, it absolutely cannot show that masks are or are not effective at reducing covid transmission. There are so many confounding factors, the results are basically meaningless. The most obvious confounding factor is of course that as covid rates rise, people are more likely to wear a mask. This by itself explains the positive correlation between mask compliance and covid rates. The paper says that the positive correlation is surprising. It is not.
- deleted 4y ago
  [deleted]
- rTX5CMRXIfFG 4y ago
  Of course you can’t always see direct causality in a complex system, but aren’t there already controlled experiments that showed that face masks reduce risk of transmission? Those were the basis for health experts to recommend the measure in the first place.
  - LudwigNagasena 4y ago
    So there were no experiments that could definitely say whether masks help against flu or SARS but with Covid-19 the science is settled?
    - chiefalchemist 4y ago
      The fact that we've had prior "events" and didn't /don't understand the strengths and weaknesses of the public health tools (e.g., various types of masks) is worrisome.
      - belorn 4y ago
        Looking at what medical professional said during the beginning on the pandemic, the general understanding of the strengths and weaknesses of mask seemed to have been fairly good. Mask are classified and tested based on medical criteria, and hospital and other industries use them during high risk situations since it has been proven effective in such scenarios. The lack of understanding was primarily when mask got taken outside the context of high risk situations and into general use in outdoor and indoor environments, and for purposes which the masks classifications don't consider. Everything from an airplane with circulated air, to people outside on a beach in the fresh breeze. On top of that we have politicians making the decision rather than medical professionals. There are however fairly low understanding of other public health tools that is outside the scope of what medical professionals can do. Shutting down mass transportation, restricting travel, shutting down social activities. Finland as an example fully closed down their capital during the start of the pandemic, preventing almost all movement in and out of the city. Looking at the graphs, that alone might have been what attribute the low case and death rates, and its not something that the medical profession has many studies on.
michalu 4y ago
It's really hard to make conclusion based on mask usage not accounting for many other factors such as population density. You have places like Finland with 5 mil people and minimum contact vs. Netherlands with 1/8 of the area and 4 times the population. Then you have France, Italy where all people kiss to greet each other and Germany where they barely shake hands etc. So don't think this is very productive study and I'm generally not in favour of mask mandates (sentiment-wise for we have yet to see reliable data) especially for recent variants.
- belorn 4y ago
  The alternative to mask mandates was selective use of mask in situation of high risk. If Netherlands is generally a high risk area while Finland is a low risk area, then that would illustrate a failure of mask mandates in favor of selective use. If that is what this study demonstrate then that is an important finding.
- Mordisquitos 4y ago
  To make it even harder, population density is itself not easy to interpret correctly. For instance, a naïve comparison on the population densities of England (432 people/km²) and Spain (94 people/km²) could lead one to believe that England would have a much tougher time than Spain at containing the spread of a contagious disease. However, the population density surrounding the average Spaniard is much higher than the density surrounding the average English person, as Spanish population tends to be much more densely urbanised into flats than the population of England.
  - iggldiggl 4y ago
    The keyword is population-weighted population density: https://www.worldpop.org/methods/pwd https://www.worldpop.org/methods/pwd
    - Mordisquitos 4y ago
      Thanks, I didn't know there was an explicit term for this (though I should have guessed). It is a pity though that the map that they use to illustrate the data is divided into administrative divisions that are not really comparable: England, Wales and Scotland for Great Britain, but all 17 autonomous communities for Spain.
IIAOPSW 4y ago
Hold up. Who the heck thought it was a good idea to put masking policy on the Y axis and deaths on the X axis. Also what the heck does Y% mask compliance mean? Does that mean Y% of people wore it 100% of the time and (1-Y%) wore it never? Or does it mean if you picked a random person at a random time, there was a Y% chance they were wearing a mask? There's a distinct lack of clarity in what exactly is being tested here. I agree with the ranking the paper has gotten so far in the side bar. Its weak point is its study design and methods. Frankly, that part reads like someone who furiously googled some data to win an online argument, not like a scientific paper.
tjansen 4y ago
Germany is currently a good testing ground for mask effectiveness. At the beginning of this month, the mask mandate has been dropped in most states, with some exceptions like public transport and hospitals. However, Mecklenburg Vorpommern and Hamburg declared themselves hotspots and kept the full indoor mask mandate, even though their infection rate was about the same as other states'. In MV it had been overturned by a court last week, but in Hamburg the mask mandate is still in effect. So far, infection rates in MV and Hamburg have been about the same as in the other states (actually a bit higher). As a caveat, there are still a lot of people wearing masks voluntarily. My guess is about 50% in super markets still wear them, with regional differences.
- q-big 4y ago
  > My guess is about 50% in super markets still wear them, with regional differences. My personal gut feeling (being German, but also having been influenced by a "privacy-consciousness bubble" ;-) ) is that there exist people who like the situation that it has become socially acceptable to wear a mask in public (without being concerned about COVID-19 in the slightest), for example because - this enables you to say a big "f... you" to surveillance cameras - this might possibly be even a socially acceptable and semi-legal way to "circumvent" the "Vermummungsverbot" on rallys (concerning "Vermummungsverbot": in Germany, you are not allowed to wear face coverings on public rallys; the police often uses this as a pretense to take action against protestors when it does not like the goal of the rally) In this spirit: Let's continue the situation that disguising yourself in public stays socially accepted. Thus, I will continue wearing a mask in public and simply give the pretense that I am still concerned about COVID-19, or that I believe to belong to a group that is more vulnerable regarding COVID-19. TLDR: Do not believe that everybody who now still wears a mask in public in Germany does this because he is afraid of COVID-19.
  - LargoLasskhyfv 4y ago
    Surveillance cam feeds into Edge-AI-Gadget, tracking your clothes, gait, whatever, saying KTHXBAI subject 08154711! Sorry for the wet nose and face.
  - 4y ago
jotm 4y ago
I liked masks. Privacy, warmth during winter, anecdotally had no cold infection in the past 2 years (usually have one every year, and I wasn't stuck at home in the worst period of Covid), protects against each others' bad breath, everyone is quieter since it's harder to talk. Everyone complaining about masks ignored all the other, more pressing problems around restrictions/Covid. It was kind of like complaining about losing a rare banknote by getting shot in a mugging. Now we're "Covid free" and no one wears one, and it's really awkward to be the only one with a mask...
- denton-scratch 4y ago
  I like masks too. I wear a blue surgical mask when I'm confined indoors (e.g. a supermarket) with a bunch of maskless wonders. The blue mask may have poor protective properties (for me), but that's not why I wear it; I wear it to protect my fellow shoppers. In fact the purpose of those surgical masks is to prevent your surgeon or dentist infecting you - not vice-versa. It seems obvious that wearing a mask will reduce the number of droplets released during exhalation. I'm a vulnerable person; I have a pre-existing lung condition. I therefore try to maintain "social distance" in addition to wearing a mask. Around here, only older people are still wearing masks, even though there's a recent flare-up locally. Impatient people in supermarket checkout queues often press up behind me, as if pushing forward is going to get them through the checkout faster. Those people annoy me more than maskless wonders. I find I like social distancing more than mask-wearing. Pandemic or not, I find I like having my personal space respected. I don't want to inhale some girl's miasma of cheap perfume, not some homeless man's stink of B.O. and booze. I never wear a mask in the fresh air. And I've received hostile comments when walking into a pub with a mask on; so I don't wear a mask in pubs (I find it's hard to drink through a mask anyway).
doubtfuluser 4y ago
Edit: in addition to the part below, I now see major flaws: Of course there is a positive correlation between masks and deaths. But the causality is important: when I see more deaths in my country, of course will I wear my mask more often. This study would have been much better if changepoints would have been looked at. In this Form there are many unknown von founders to draw conclusions in my opinion. For now I keep my doubts on this study. Before edit: Can someone shed light on the trustworthiness of that publication website as well as the author? Is “cureus” a trusted resource? I’m always doubtful if there is only one author on a paper - unless it’s a really well known person. COVID-19 was used by far too many as a vehicle to push their profile or agendas. This result seems to be quite in contrast to the investigations famous labs and institutions did (like RKI and the likes)
dash2 4y ago
Just this comment again: https://news.ycombinator.com/item?id=31158391 https://news.ycombinator.com/item?id=31158391 :-(
- artemonster 4y ago
  At this point the famous „correlation is not causaution“ quote is so abused that its on par with „goto is bad“. Studying correlation does not dismiss the research itself
  - dash2 4y ago
    But here it's really important, because people might mistakenly believe that this research proves that (a) you shouldn't wear a mask (b) you shouldn't tell people to wear masks.
- ltbarcly3 4y ago
  No, that comment does not apply here at all. The saying is "Correlation does not imply Causation". This saying is correct, you can have correlation for lots of reasons without a causal relationship. However, causation does imply correlation. You cannot have causation without correlation. The contra-positive of this is no-correlation implies no-causation. This study shows a lack of correlation in the data that they have, which does, within the limitations of that data, imply a lack of causation. There could be confounding factors here, but it isn't completely irrational to think that wearing a cotton mask that only filters out about 10% of the particles in question (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185834/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185834/) might not be very effective at preventing transmission. If not, it is important that governments start stockpiling effective masks to prepare for future virus outbreaks.
  - dash2 4y ago
    You are mistaken. You can have causation without correlation. For example, suppose my umbrella keeps me dry. But I only take my umbrella out when it's raining. The correlation between my taking my umbrella and my being wet is zero: I either don't get rained on because I have an umbrella, or because it isn't raining; I'm only wet from other causes, unrelated to umbrellas or rain. However, my umbrella causes me to be dry. If I didn't take my umbrella out, holding everything else constant, I would get wet. Here are more details and examples: https://theincidentaleconomist.com/wordpress/causation-without-correlation-is-possible/ https://theincidentaleconomist.com/wordpress/causation-witho... In this case, it's quite possible that (a) mask-wearing keeps you safe but (b) mask-wearing is only brought in when Covid is bad; and that the two countervailing effects lead to an estimated correlation of zero.
tyho 4y ago
The fact that there is no CLEAR evidence that masks are effective at improving COVID outcomes tells you that if they do have an effect, the size must be small. If they worked well, anywhere near say preventing 50% of infections, then you would not need complicated statistical analysis to tease out marginal hazard ratios from massive data sets.
- DoingIsLearning 4y ago
  I think the biggest problem is putting _all_ masks in the same bucket. The selection criteria is too wide. I have used 'duck beak' ffp3 masks through several flights during peak pandemic, and I had to physically workout my chest muscles to take a full breath of air in. I have also bought disposable masks online that were paper mache level. Both cases are 'people wearing masks' but I can guarantee that these two masks are not having the same effect. We can argue logistics and feasibility of everyone using ffp3 masks, but claiming that masks don't have clear evidence is to ignore the whole physics of filtration.
  - qeternity 4y ago
    And then you rub your eyes as you nod off for a nap on the plane. We know that airborne transmission has been a small piece of the puzzle. But masks are visible and so the only thing we could do for security theater. And we turned the response into this virtue signaling debate. Even this thread has people bending over backwards to defend their views...that's not how science works! I do not believe that masks _increase_ mortality. But I think it's pretty clear that masks have minimal, if any, impact on transmission.
    - DoingIsLearning 4y ago
      > We know that airborne transmission has been a small piece of the puzzle. Do you have a quote for this claim? Everything I read is claiming the exact opposite, that authorities overstated the contact surface transmission and that the majority of SARS-COV2 infections occur through droplets or aerosol.
    - 4y ago
chiefalchemist 4y ago
> These findings indicate that countries with high levels of mask compliance did not perform better than those with low mask usage. That could be because the majority of masks (e.g., the ultra-cheap blue ones) are - per the CDC - all but useless. That is, wear a mask (that's no mask at all) and you're all but unmasked. Oddly enough, currently, (e.g.) Philadelphia reinstated an indoor mask mandate, but made no requirement for an effective mask (according to the data / science). It makes no sense.
- q-big 4y ago
  > That is, wear a mask (that's no mask at all) and you're all but unmasked. Possibly even worse: you feel better protected as thus behave more riskily with respect to COVID-19 transmission. Keyword: risk compensation > https://en.wikipedia.org/wiki/Risk_compensation https://en.wikipedia.org/wiki/Risk_compensation
xkbarkar 4y ago
Two years later. Actual imerial data have shown zero impact on mask wearing and transmission rates among the public. And still forums cling on to subpar research like this. Masks among the public have done a fantatic job of filling the oceans with garbage. Nothing positive came out of the mask mandates. Not a single positive aspect. Mask, visors and goggles among healthcare personell are completely different. Takes a few minutes to suit up. And can be so painful that the people wearing them have bruises on their faces. But they protect the wearer and zero slogans out there have yelled masks on all hospital workers to protect the patients. Never was the case. Jesus the obsession with forcing one another to cover our faces ( in US even small toddler for crying out loud ), is closer to saudi or taliban religious dogma than science. Crazy world. Masks in restaurants. Cafees. Masked servent around maskless famous people. During strenous excercise. On small children where they are absolutely a choking hazard, so masks during playtime but masks off during collective naptime. All the masks on the streets, in bushes and trees and flying about especially around bus stations and stores. Disposable pink chinese surgical mask on a hipster wearing a save the wales tshirt where there are no madates is about as cringe as it gets.
- manwe150 4y ago
  I assume this was a phone typo, but now I want to know if “save the wales” shirts get sold in Great Britain in any tourist shops, or only to the native hipsters there?
scotty79 4y ago
How to drown any effect in the random sea of confounding factors but still claim correlation an potential causality in the end. > the moderate positive correlation between mask usage and deaths in Western Europe also suggests that the universal use of masks may have had harmful unintended consequences. Or people in countries with higher mortality were slightly more likely to wear masks.
MarkusWandel 4y ago
One argument I've seen against the use of bike helmets is that people naturally gravitate to a certain risk level. Thus helmet wearing, it is argued, leads directly to a slightly more risk-taking style of cycling which cancels out the safety benefit of the helmet. Agree with that or not (I personally argue that my head is disproportionately in need of protection compared to other body parts - I had a crash that broke the helmet into three pieces and broke my collarbone - but no harm done to my head) - but the same could be said about masks. I've seen many ineffective masks - simple cloth, worn with big gaps around the nose, even ski masks at the ski hill that have a vent for the nose. But now that we're masked, we're doing our thing, we can relax, right? So the usual mob scene at Costco with not even token attempts to keep distance. Would absence of masks cause people to be more cautious?
- sjg007 4y ago
  >One argument I've seen against the use of bike helmets is that people naturally gravitate to a certain risk level. Thus helmet wearing, it is argued, leads directly to a slightly more risk-taking style of cycling which cancels out the safety benefit of the helmet. This is a nonsensical argument. Do you drive your car 100mph because you have airbags and a seatbelt? If you wore a helmet in the car would you do so? Masks do not encourage riskier behavior either. It makes current behavior safer that's all.
  - n4r9 4y ago
    If I _didn't_ have airbags or a seatbelt I wouldn't even go over 30mph.
    - drugstorecowboy 4y ago
      You are certainly in the minority though, given that millions of people drove much faster than 30mph daily for many many years with neither. Seatbelts weren't even required in cars in the US until 1968, airbags in the 90's. Anecdotally, neither I nor anyone I know thinks this way, the availability of a seatbelt or airbag isn't the determining factor in my driving speed by any measure.
antisinguIarity 4y ago
I see a lot of comments conflating the mask types, and exactly who is being protected. Just to put us all on a common footing, here is a reminder of what the public messaging (at least, here in the UK) has been for two years: Any mask is essential for us to protect others. At no point has it been shown that a mask-like face covering of unspecified material provides any significant degree of protection to the wearer against airbourne viruses. It's still fairly controversial to suggest that mass mask-wearing of cloth masks may not have done much public good anyway. It's pretty clear that a mask that is actually rated to filter to a certain level will protect the wearer, but then those masks typically have a valve to relieve the extra load on the wearer's respiratory system. Obviously, these masks will also not "protect others', as they dump all of your exhaled air right back into the vicinity.
- manwe150 4y ago
  In the studies I thought they were mainly quoting for that, I thought they usually showed there was similar reductions in both directions, but a greater reduction for source masking. That message somehow then got turned into there being no filtering for inhaling and that a masks only purpose is to protect others All that being strongly dependent on picking a mask that has decent filtration though, since many don’t and only some do.
  - antisinguIarity 4y ago
    Which studies? >All that being strongly dependent on picking a mask that has decent filtration though Like I said, masks rated for the job will do the job (of filtering the air you are breathing into your lungs).
dfawcus 4y ago
One problem with the data is that they have distinct entries for United Kingdom and Northern Ireland, yet the latter is part of the former. So does United Kingdom as used in the table actually mean Great Britain, or are the NI figures actually also included in the UK figures? If they were/are distinct, non sub-setted, data sets, then they'd possibly make a useful comparison, but without that extra info it is impossible to interpret those numbers.
seasoup 4y ago
What this study shows is that when infection rates are high people wear masks, and conversely, that when people wear masks infection rates are high. Or put another way, it either shows that high infection rates cause people to wear masks, that wearing masks causes high infection rates, or that neither causes the other but some tertiary value not part of the study causes both to rise and fall in tandem. It does not effectively demonstrate the amount that wearing a mask raises, or reduces, infection rates.

75 points by shaicoleman 4y ago

deleted 4y ago

[deleted]

Conclusions > While no cause-effect conclusions could be inferred from this observational analysis, the lack of negative correlations between mask usage and COVID-19 cases and deaths suggest that the widespread use of masks at a time when an effective intervention was most needed, i.e., during the strong 2020-2021 autumn-winter peak, was not able to reduce COVID-19 transmission. Moreover, the moderate positive correlation between mask usage and deaths in Western Europe also suggests that the universal use of masks may have had harmful unintended consequences.

adamredwoods 4y ago
Dangerous conclusions, attempting to convince people that wearing masks is harmful. So many assumptions are made that this 'correlation' gives little insight. For example, place of case infection is not even considered. If most people become infected at gatherings where their mask is left off, but they wear their mask in public, then how is this factored? Or perhaps those who wore masks more frequently were at greater risk of infection? I've been to the hospital recently, and have witnessed the extreme use of masks there. They would laugh at this article.

maneesh 4y ago

The one sentence summary: “These findings indicate that countries with high levels of mask compliance did not perform better than those with low mask usage.“ Should this source be trusted or not? If it’s trusted, does that mean that our efforts to mask were basically a waste of time, or not?

hannob 4y ago
1. It's a publication with post-publication peer review. Meaning: It's not been peer reviewed before publication. That's not invalidating its findings, but it's evidence one should rate as potentially of lower quality until other experts have reviewed it. 2. You should never look at one study, but at all the evidence. It is generally difficult to study the effects of something like mask wearing, as you can't easily do something like an RCT (or if you try it may not tell you what you wanted to learn, i.e. it's even harder to test if others are protected by mask wearing). There are no easy answers, but it's been my impression that experts reviewing all the evidence in the past came to the conclusion that mask wearing likely works quite well.
- elcritch 4y ago
  A single study generally isn't conclusive, especially in a field with as many confounding factors as public health policies. It'll take a lot of time and hard work to decisively say if there's an effect and to what degree. The various studies and meta-analysis I've read appear to indicate that masks somewhat slowed the transmission rate, but overall didn't greatly reduce final case counts. There's enough uncertainty that I believe we'll need solid RCTs to get better answers. There was on large RCT slated to happen in west African country (Rwanda maybe?) where covid-19 hadn't hit.
systoll 4y ago
> Should this source be trusted or not? Seems legitimate, though that doesn’t mean it’s a particularly valuable analysis. > If it’s trusted, does that mean that our efforts to mask were basically a waste of time, or not? It doesn't say. In a world where everyone wakes up each day, checks the daily cases nearby, and only puts on a mask if it’s over 1000… you'd get near perfect correlation between mask use & covid cases, even if the masks prevent every single transmission. And that’s not all that out of line with reality. High rates of Covid absolutely cause increased levels of mask compliance, so seeing a correlation between the two doesn't really tell us much about mask effectiveness. You could maybe do some time-series analysis to try and get a better idea. The decision to mask today would be influenced by cases in the recent past, and any actual effect of mask wearing would only affect diagnoses 3-5 days later. But I’ve not done that math, and neither has this paper.

mnw21cam 4y ago

While this is a very interesting study, it absolutely cannot show that masks are or are not effective at reducing covid transmission. There are so many confounding factors, the results are basically meaningless. The most obvious confounding factor is of course that as covid rates rise, people are more likely to wear a mask. This by itself explains the positive correlation between mask compliance and covid rates. The paper says that the positive correlation is surprising. It is not.

deleted 4y ago
[deleted]
rTX5CMRXIfFG 4y ago
Of course you can’t always see direct causality in a complex system, but aren’t there already controlled experiments that showed that face masks reduce risk of transmission? Those were the basis for health experts to recommend the measure in the first place.
- LudwigNagasena 4y ago
  So there were no experiments that could definitely say whether masks help against flu or SARS but with Covid-19 the science is settled?
  - chiefalchemist 4y ago
    The fact that we've had prior "events" and didn't /don't understand the strengths and weaknesses of the public health tools (e.g., various types of masks) is worrisome.
    - belorn 4y ago
      Looking at what medical professional said during the beginning on the pandemic, the general understanding of the strengths and weaknesses of mask seemed to have been fairly good. Mask are classified and tested based on medical criteria, and hospital and other industries use them during high risk situations since it has been proven effective in such scenarios. The lack of understanding was primarily when mask got taken outside the context of high risk situations and into general use in outdoor and indoor environments, and for purposes which the masks classifications don't consider. Everything from an airplane with circulated air, to people outside on a beach in the fresh breeze. On top of that we have politicians making the decision rather than medical professionals. There are however fairly low understanding of other public health tools that is outside the scope of what medical professionals can do. Shutting down mass transportation, restricting travel, shutting down social activities. Finland as an example fully closed down their capital during the start of the pandemic, preventing almost all movement in and out of the city. Looking at the graphs, that alone might have been what attribute the low case and death rates, and its not something that the medical profession has many studies on.

michalu 4y ago

It's really hard to make conclusion based on mask usage not accounting for many other factors such as population density. You have places like Finland with 5 mil people and minimum contact vs. Netherlands with 1/8 of the area and 4 times the population. Then you have France, Italy where all people kiss to greet each other and Germany where they barely shake hands etc. So don't think this is very productive study and I'm generally not in favour of mask mandates (sentiment-wise for we have yet to see reliable data) especially for recent variants.

belorn 4y ago
The alternative to mask mandates was selective use of mask in situation of high risk. If Netherlands is generally a high risk area while Finland is a low risk area, then that would illustrate a failure of mask mandates in favor of selective use. If that is what this study demonstrate then that is an important finding.
Mordisquitos 4y ago
To make it even harder, population density is itself not easy to interpret correctly. For instance, a naïve comparison on the population densities of England (432 people/km²) and Spain (94 people/km²) could lead one to believe that England would have a much tougher time than Spain at containing the spread of a contagious disease. However, the population density surrounding the average Spaniard is much higher than the density surrounding the average English person, as Spanish population tends to be much more densely urbanised into flats than the population of England.
- iggldiggl 4y ago
  The keyword is population-weighted population density: https://www.worldpop.org/methods/pwd https://www.worldpop.org/methods/pwd
  - Mordisquitos 4y ago
    Thanks, I didn't know there was an explicit term for this (though I should have guessed). It is a pity though that the map that they use to illustrate the data is divided into administrative divisions that are not really comparable: England, Wales and Scotland for Great Britain, but all 17 autonomous communities for Spain.

IIAOPSW 4y ago

Hold up. Who the heck thought it was a good idea to put masking policy on the Y axis and deaths on the X axis. Also what the heck does Y% mask compliance mean? Does that mean Y% of people wore it 100% of the time and (1-Y%) wore it never? Or does it mean if you picked a random person at a random time, there was a Y% chance they were wearing a mask? There's a distinct lack of clarity in what exactly is being tested here. I agree with the ranking the paper has gotten so far in the side bar. Its weak point is its study design and methods. Frankly, that part reads like someone who furiously googled some data to win an online argument, not like a scientific paper.

tjansen 4y ago

Germany is currently a good testing ground for mask effectiveness. At the beginning of this month, the mask mandate has been dropped in most states, with some exceptions like public transport and hospitals. However, Mecklenburg Vorpommern and Hamburg declared themselves hotspots and kept the full indoor mask mandate, even though their infection rate was about the same as other states'. In MV it had been overturned by a court last week, but in Hamburg the mask mandate is still in effect. So far, infection rates in MV and Hamburg have been about the same as in the other states (actually a bit higher). As a caveat, there are still a lot of people wearing masks voluntarily. My guess is about 50% in super markets still wear them, with regional differences.

q-big 4y ago
> My guess is about 50% in super markets still wear them, with regional differences. My personal gut feeling (being German, but also having been influenced by a "privacy-consciousness bubble" ;-) ) is that there exist people who like the situation that it has become socially acceptable to wear a mask in public (without being concerned about COVID-19 in the slightest), for example because - this enables you to say a big "f... you" to surveillance cameras - this might possibly be even a socially acceptable and semi-legal way to "circumvent" the "Vermummungsverbot" on rallys (concerning "Vermummungsverbot": in Germany, you are not allowed to wear face coverings on public rallys; the police often uses this as a pretense to take action against protestors when it does not like the goal of the rally) In this spirit: Let's continue the situation that disguising yourself in public stays socially accepted. Thus, I will continue wearing a mask in public and simply give the pretense that I am still concerned about COVID-19, or that I believe to belong to a group that is more vulnerable regarding COVID-19. TLDR: Do not believe that everybody who now still wears a mask in public in Germany does this because he is afraid of COVID-19.
- LargoLasskhyfv 4y ago
  Surveillance cam feeds into Edge-AI-Gadget, tracking your clothes, gait, whatever, saying KTHXBAI subject 08154711! Sorry for the wet nose and face.
- 4y ago

jotm 4y ago

I liked masks. Privacy, warmth during winter, anecdotally had no cold infection in the past 2 years (usually have one every year, and I wasn't stuck at home in the worst period of Covid), protects against each others' bad breath, everyone is quieter since it's harder to talk. Everyone complaining about masks ignored all the other, more pressing problems around restrictions/Covid. It was kind of like complaining about losing a rare banknote by getting shot in a mugging. Now we're "Covid free" and no one wears one, and it's really awkward to be the only one with a mask...

denton-scratch 4y ago
I like masks too. I wear a blue surgical mask when I'm confined indoors (e.g. a supermarket) with a bunch of maskless wonders. The blue mask may have poor protective properties (for me), but that's not why I wear it; I wear it to protect my fellow shoppers. In fact the purpose of those surgical masks is to prevent your surgeon or dentist infecting you - not vice-versa. It seems obvious that wearing a mask will reduce the number of droplets released during exhalation. I'm a vulnerable person; I have a pre-existing lung condition. I therefore try to maintain "social distance" in addition to wearing a mask. Around here, only older people are still wearing masks, even though there's a recent flare-up locally. Impatient people in supermarket checkout queues often press up behind me, as if pushing forward is going to get them through the checkout faster. Those people annoy me more than maskless wonders. I find I like social distancing more than mask-wearing. Pandemic or not, I find I like having my personal space respected. I don't want to inhale some girl's miasma of cheap perfume, not some homeless man's stink of B.O. and booze. I never wear a mask in the fresh air. And I've received hostile comments when walking into a pub with a mask on; so I don't wear a mask in pubs (I find it's hard to drink through a mask anyway).

doubtfuluser 4y ago

Edit: in addition to the part below, I now see major flaws: Of course there is a positive correlation between masks and deaths. But the causality is important: when I see more deaths in my country, of course will I wear my mask more often. This study would have been much better if changepoints would have been looked at. In this Form there are many unknown von founders to draw conclusions in my opinion. For now I keep my doubts on this study. Before edit: Can someone shed light on the trustworthiness of that publication website as well as the author? Is “cureus” a trusted resource? I’m always doubtful if there is only one author on a paper - unless it’s a really well known person. COVID-19 was used by far too many as a vehicle to push their profile or agendas. This result seems to be quite in contrast to the investigations famous labs and institutions did (like RKI and the likes)

dash2 4y ago

Just this comment again: https://news.ycombinator.com/item?id=31158391 https://news.ycombinator.com/item?id=31158391 :-(

artemonster 4y ago
At this point the famous „correlation is not causaution“ quote is so abused that its on par with „goto is bad“. Studying correlation does not dismiss the research itself
- dash2 4y ago
  But here it's really important, because people might mistakenly believe that this research proves that (a) you shouldn't wear a mask (b) you shouldn't tell people to wear masks.
ltbarcly3 4y ago
No, that comment does not apply here at all. The saying is "Correlation does not imply Causation". This saying is correct, you can have correlation for lots of reasons without a causal relationship. However, causation does imply correlation. You cannot have causation without correlation. The contra-positive of this is no-correlation implies no-causation. This study shows a lack of correlation in the data that they have, which does, within the limitations of that data, imply a lack of causation. There could be confounding factors here, but it isn't completely irrational to think that wearing a cotton mask that only filters out about 10% of the particles in question (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185834/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185834/) might not be very effective at preventing transmission. If not, it is important that governments start stockpiling effective masks to prepare for future virus outbreaks.
- dash2 4y ago
  You are mistaken. You can have causation without correlation. For example, suppose my umbrella keeps me dry. But I only take my umbrella out when it's raining. The correlation between my taking my umbrella and my being wet is zero: I either don't get rained on because I have an umbrella, or because it isn't raining; I'm only wet from other causes, unrelated to umbrellas or rain. However, my umbrella causes me to be dry. If I didn't take my umbrella out, holding everything else constant, I would get wet. Here are more details and examples: https://theincidentaleconomist.com/wordpress/causation-without-correlation-is-possible/ https://theincidentaleconomist.com/wordpress/causation-witho... In this case, it's quite possible that (a) mask-wearing keeps you safe but (b) mask-wearing is only brought in when Covid is bad; and that the two countervailing effects lead to an estimated correlation of zero.

tyho 4y ago

The fact that there is no CLEAR evidence that masks are effective at improving COVID outcomes tells you that if they do have an effect, the size must be small. If they worked well, anywhere near say preventing 50% of infections, then you would not need complicated statistical analysis to tease out marginal hazard ratios from massive data sets.

DoingIsLearning 4y ago
I think the biggest problem is putting _all_ masks in the same bucket. The selection criteria is too wide. I have used 'duck beak' ffp3 masks through several flights during peak pandemic, and I had to physically workout my chest muscles to take a full breath of air in. I have also bought disposable masks online that were paper mache level. Both cases are 'people wearing masks' but I can guarantee that these two masks are not having the same effect. We can argue logistics and feasibility of everyone using ffp3 masks, but claiming that masks don't have clear evidence is to ignore the whole physics of filtration.
- qeternity 4y ago
  And then you rub your eyes as you nod off for a nap on the plane. We know that airborne transmission has been a small piece of the puzzle. But masks are visible and so the only thing we could do for security theater. And we turned the response into this virtue signaling debate. Even this thread has people bending over backwards to defend their views...that's not how science works! I do not believe that masks _increase_ mortality. But I think it's pretty clear that masks have minimal, if any, impact on transmission.
  - DoingIsLearning 4y ago
    > We know that airborne transmission has been a small piece of the puzzle. Do you have a quote for this claim? Everything I read is claiming the exact opposite, that authorities overstated the contact surface transmission and that the majority of SARS-COV2 infections occur through droplets or aerosol.
  - 4y ago

chiefalchemist 4y ago

> These findings indicate that countries with high levels of mask compliance did not perform better than those with low mask usage. That could be because the majority of masks (e.g., the ultra-cheap blue ones) are - per the CDC - all but useless. That is, wear a mask (that's no mask at all) and you're all but unmasked. Oddly enough, currently, (e.g.) Philadelphia reinstated an indoor mask mandate, but made no requirement for an effective mask (according to the data / science). It makes no sense.

q-big 4y ago
> That is, wear a mask (that's no mask at all) and you're all but unmasked. Possibly even worse: you feel better protected as thus behave more riskily with respect to COVID-19 transmission. Keyword: risk compensation > https://en.wikipedia.org/wiki/Risk_compensation https://en.wikipedia.org/wiki/Risk_compensation

xkbarkar 4y ago

Two years later. Actual imerial data have shown zero impact on mask wearing and transmission rates among the public. And still forums cling on to subpar research like this. Masks among the public have done a fantatic job of filling the oceans with garbage. Nothing positive came out of the mask mandates. Not a single positive aspect. Mask, visors and goggles among healthcare personell are completely different. Takes a few minutes to suit up. And can be so painful that the people wearing them have bruises on their faces. But they protect the wearer and zero slogans out there have yelled masks on all hospital workers to protect the patients. Never was the case. Jesus the obsession with forcing one another to cover our faces ( in US even small toddler for crying out loud ), is closer to saudi or taliban religious dogma than science. Crazy world. Masks in restaurants. Cafees. Masked servent around maskless famous people. During strenous excercise. On small children where they are absolutely a choking hazard, so masks during playtime but masks off during collective naptime. All the masks on the streets, in bushes and trees and flying about especially around bus stations and stores. Disposable pink chinese surgical mask on a hipster wearing a save the wales tshirt where there are no madates is about as cringe as it gets.

manwe150 4y ago
I assume this was a phone typo, but now I want to know if “save the wales” shirts get sold in Great Britain in any tourist shops, or only to the native hipsters there?

scotty79 4y ago

How to drown any effect in the random sea of confounding factors but still claim correlation an potential causality in the end. > the moderate positive correlation between mask usage and deaths in Western Europe also suggests that the universal use of masks may have had harmful unintended consequences. Or people in countries with higher mortality were slightly more likely to wear masks.

MarkusWandel 4y ago

One argument I've seen against the use of bike helmets is that people naturally gravitate to a certain risk level. Thus helmet wearing, it is argued, leads directly to a slightly more risk-taking style of cycling which cancels out the safety benefit of the helmet. Agree with that or not (I personally argue that my head is disproportionately in need of protection compared to other body parts - I had a crash that broke the helmet into three pieces and broke my collarbone - but no harm done to my head) - but the same could be said about masks. I've seen many ineffective masks - simple cloth, worn with big gaps around the nose, even ski masks at the ski hill that have a vent for the nose. But now that we're masked, we're doing our thing, we can relax, right? So the usual mob scene at Costco with not even token attempts to keep distance. Would absence of masks cause people to be more cautious?

sjg007 4y ago
>One argument I've seen against the use of bike helmets is that people naturally gravitate to a certain risk level. Thus helmet wearing, it is argued, leads directly to a slightly more risk-taking style of cycling which cancels out the safety benefit of the helmet. This is a nonsensical argument. Do you drive your car 100mph because you have airbags and a seatbelt? If you wore a helmet in the car would you do so? Masks do not encourage riskier behavior either. It makes current behavior safer that's all.
- n4r9 4y ago
  If I _didn't_ have airbags or a seatbelt I wouldn't even go over 30mph.
  - drugstorecowboy 4y ago
    You are certainly in the minority though, given that millions of people drove much faster than 30mph daily for many many years with neither. Seatbelts weren't even required in cars in the US until 1968, airbags in the 90's. Anecdotally, neither I nor anyone I know thinks this way, the availability of a seatbelt or airbag isn't the determining factor in my driving speed by any measure.

antisinguIarity 4y ago

I see a lot of comments conflating the mask types, and exactly who is being protected. Just to put us all on a common footing, here is a reminder of what the public messaging (at least, here in the UK) has been for two years: Any mask is essential for us to protect others. At no point has it been shown that a mask-like face covering of unspecified material provides any significant degree of protection to the wearer against airbourne viruses. It's still fairly controversial to suggest that mass mask-wearing of cloth masks may not have done much public good anyway. It's pretty clear that a mask that is actually rated to filter to a certain level will protect the wearer, but then those masks typically have a valve to relieve the extra load on the wearer's respiratory system. Obviously, these masks will also not "protect others', as they dump all of your exhaled air right back into the vicinity.

manwe150 4y ago
In the studies I thought they were mainly quoting for that, I thought they usually showed there was similar reductions in both directions, but a greater reduction for source masking. That message somehow then got turned into there being no filtering for inhaling and that a masks only purpose is to protect others All that being strongly dependent on picking a mask that has decent filtration though, since many don’t and only some do.
- antisinguIarity 4y ago
  Which studies? >All that being strongly dependent on picking a mask that has decent filtration though Like I said, masks rated for the job will do the job (of filtering the air you are breathing into your lungs).

dfawcus 4y ago

One problem with the data is that they have distinct entries for United Kingdom and Northern Ireland, yet the latter is part of the former. So does United Kingdom as used in the table actually mean Great Britain, or are the NI figures actually also included in the UK figures? If they were/are distinct, non sub-setted, data sets, then they'd possibly make a useful comparison, but without that extra info it is impossible to interpret those numbers.

seasoup 4y ago

What this study shows is that when infection rates are high people wear masks, and conversely, that when people wear masks infection rates are high. Or put another way, it either shows that high infection rates cause people to wear masks, that wearing masks causes high infection rates, or that neither causes the other but some tertiary value not part of the study causes both to rise and fall in tandem. It does not effectively demonstrate the amount that wearing a mask raises, or reduces, infection rates.