Face masks effectively limit the probability of SARS-CoV-2 transmission • Hacker News Board

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#351

Post by asabjorn » Fri, May 21, 2021, 3:33 PM UTC

kelnos wrote: post #273

asabjorn wrote: post #253

Earlier quoted context omitted.

> N95/FFP2 seem to be very effective. Why does then the states with the highest mask use (CA, NYC) have much higher covid positive rates than states with some of the lowest mask use (Florida, NYC)? > Education is key to understanding. You can't reach everyone most. N95 masks improperly used will hold covid for 24hrs and spread them by the incessant touching most people do of their masks before they touch other things…

> Why does then the states with the highest mask use (CA, NYC) have much higher covid positive rates than states with some of the lowest mask use (Florida, NYC)? They don't. Stop spreading misinformation. (Also I love that in this repeat of your misinformation, you accidentally typed "NYC" where you meant to say "Texas". And it would behoove you to learn the difference between a city and a state.)

The confirmed cases to population is 10.3% for NY (not NYC- 2.08m cases to 19.4m population), 9.5% for CA (3.77m cases over 39.5m population), 10.1% for texas (2.93m cases over 29m population), 10.6% for Florida (2.29/21.48).

So to be accurate the confirmed covid cases to the population is about the same in states with and without mask mandated as well as other strict social distancing measures.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#352

Post by asabjorn » Fri, May 21, 2021, 3:39 PM UTC

chimprich wrote: post #328

asabjorn wrote: post #253

Earlier quoted context omitted.

> N95/FFP2 seem to be very effective. Why does then the states with the highest mask use (CA, NYC) have much higher covid positive rates than states with some of the lowest mask use (Florida, NYC)? > Education is key to understanding. You can't reach everyone most. N95 masks improperly used will hold covid for 24hrs and spread them by the incessant touching most people do of their masks before they touch other things…

> Why does then the states with the highest mask use (CA, NYC) have much higher covid positive rates than states with some of the lowest mask use (Florida, NYC)? Even if that was true, places that were hit hardest by the pandemic tended to impose the most severe restrictions. It's like finding that crash barriers are installed on roads with the highest accident rate and asking whether crash barriers are useless.

People have traveled and moved extensively to Florida as well as TX from NY and CA, so any high-spread virus would spread to Florida and CA then spread within them.

If masks and other strict lockdown measures were effective then by now open states such as Florida and NYC would see much higher death as well as covid case rates. See other comment I made in parent thread showing its about the same.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#353

Post by dragonwriter » Fri, May 21, 2021, 3:41 PM UTC

asabjorn wrote: post #348

dragonwriter wrote: post #256

Earlier quoted context omitted.

> If so, why does states with the highest mask use (CA, NYC) have much higher covid rates than states with some of the lowest mask use (Florida, Texas)? They...don’t (leaving out NYC because the other three things are large, diverse states and NYC is a single large city): California 3.7M cumulative cases & 1,336 case/day current 7-day average vs. 39.5M population Florida 2.3M cumulative cases & 3,007 case/day 7-day a…

NY (not NYC) cumulative cases is 2m and population is 19.4m, so about 10.3% of population [source: google coronavius stats]. > California 3.7M cumulative cases & 1,336 case/day current 7-day average vs. 39.5M population Its 3.77M, so about 9.5% of population. > Texas 2.9M cumulative case & 2,034 case/day current 7-day average vs. 29M population. That's 10%. > Florida 2.3M cumulative cases & 3,007 case/day 7-day avera…

> With the total cases being about the same so this does not support your conclusion

I didn’t offer any conclusion except that the upthread claim that California had a much higher rate of COVID cases than FL/TX was bunk. To actually tease out the effects of mask use from jurisdictional case statistics, you’d also have to (1) have stats on mask use, which (despite people making claims about it in coordination with blatantly false claims about cases), I haven’t seen, and (2) have good stats for the other things that would reasonably be expected to contribute to differences in infection spread, (3) either have enough a priori knowledge of the contribution of the items in 2 to control for their effect in 1:1 comparisons, or have data from enough different places to do an analysis that determines the contributions of different factors.

Even with good mask stats, a head to head comparison of a couple states case numbers with mask stats wouldn’t otherwise be useful for anything.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#354

Post by dragonwriter » Fri, May 21, 2021, 3:44 PM UTC

asabjorn wrote: post #349

johbjo wrote: post #313

Earlier quoted context omitted.

Also consider age distribution/population density in areas you compare. Death rate is exponential in age, so small differences in age distribution gives big differences in relative deaths.

Death rate to confirmed cases is TX 1.7% (51k deaths over 2.9m cases), Florida 1.56% (36k deaths over 2296 cases), CA 1.64% (62k deaths over 3.74m cases) [source: google coronovirus stats]. So data does not confirm your conclusion.

Without stats on the age distribution of confirmed cases (even before considering the absence of analysis of confounding factors, liking case timing within the pandemic, etc.), I’m not sure how you can say the data doesn’t confirm the conclusion since you don’t have data on the proposed independent variable at all.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#355

Post by chimprich » Fri, May 21, 2021, 3:51 PM UTC

asabjorn wrote: post #352

chimprich wrote: post #328

Earlier quoted context omitted.

> Why does then the states with the highest mask use (CA, NYC) have much higher covid positive rates than states with some of the lowest mask use (Florida, NYC)? Even if that was true, places that were hit hardest by the pandemic tended to impose the most severe restrictions. It's like finding that crash barriers are installed on roads with the highest accident rate and asking whether crash barriers are useless.

People have traveled and moved extensively to Florida as well as TX from NY and CA, so any high-spread virus would spread to Florida and CA then spread within them. If masks and other strict lockdown measures were effective then by now open states such as Florida and NYC would see much higher death as well as covid case rates. See other comment I made in parent thread showing its about the same.

Strict lockdowns are effective. It's a virus that spreads through social contact. You restrict social contact, you reduce spread of the virus. It's not plausible to claim they're not effective.

This feels like an argument from 12 months ago. They've demonstrably worked in Italy, the UK, New Zealand, China, and so on. They were the primary tool to constrain virus spread until vaccines came along.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#356

Post by astrange » Fri, May 21, 2021, 3:56 PM UTC

collyw wrote: post #340

astrange wrote: post #295

Earlier quoted context omitted.

If you watched reddit all the comments to all news from China (including doctors dying, doctors not dying, hospitals being built or filling up, doctors clapping on TikTok because they'd released their last patients) was complaining about it and calling it fake news from the CCP. They were happy about the same thing from the US though.

Do you remember the posts about people dropping dead in the streets, people skin turning black, or massive cement mixers "disinfecting" streets? There was plenty of fake news going around.

The people spraying disinfectant everywhere was a bit silly but also not any different from what we were doing. At the time people out here were keeping their mail outside for 3 days and sanitizing their groceries.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#357

Post by admax88q » Fri, May 21, 2021, 3:56 PM UTC

mhb wrote: post #330

admax88q wrote: post #212

Earlier quoted context omitted.

I wear mine alone in the car or on the sidewalk frequently. Not because I'm "afraid" but because I'm too lazy to take it on and off between every stop I'm going to make. This attitude that people are wearing masks alone because they're afraid and/or stupid is toxic.

Grant me the steel man. What's the mental model of the people wearing them outside on a walk in the woods or on a beach? Not the inconvenience of taking them off between stops at the bank and the drug store.

I don't know, but who cares. Maybe for pollen and dust allergies.

Part of the problem is everyone feels the need to judge others. Why does it bother you that people wear masks on the beach? Why can't you just let them be?

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#358

Post by beagle3 » Fri, May 21, 2021, 5:01 PM UTC

dragonwriter wrote: post #345

beagle3 wrote: post #270

Earlier quoted context omitted.

I don’t know the details here, but in the Israel vs Sweden comparison, absolute numbers favor Israel (7000 vs 14000 dead) but age normalized are the same (Sweden has about twice as many >60), and in European normalized excess death measures from Oxford, Sweden is at 2% and Israel at 6% Personally, I try to only use excess death figures, because case counts are not comparable due to local policies. E.g. once vaccinati…

> Personally, I try to only use excess death figures, because case counts are not comparable due to local policies. Deaths are great measure of how bad you’ve been hit overall, but even if they (when you use excess rather than COVID-attributed deaths) are arguably more reliable numbers, they are a much worse proxy when you are trying to compare effectiveness specifically of infection control measures..That’s because…

It is far from perfect; and yet, it's the only metric comparable between different countries, assuming you can trust death counts -- which I do for most countries. It's not a good proxy, but there is no better one that I've found (nor that I'm aware anyone else has found).

Every other measure has all of the problems you listed, and in addition it is subject to testing policy differences (including who to test, cycle threshold, and other variables), diagnostic policy differences (e.g., in the UK, death within 28 days of a positive PCR test is classified as death from corona, regardless of what happened since; Death more than 24 hours from a vaccine is assumed unrelated to the vaccine), and explicit number fudging.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#359

Post by greggman3 » Fri, May 21, 2021, 5:21 PM UTC

astrange wrote: post #299

greggman3 wrote: post #278

Earlier quoted context omitted.

I haven't clue about statics so it's likely this is wrong but a quick graph of COVID deaths per million vs obesity rate for each country doesn't look like there is any correlation. https://jsgist.org/?src=7b456a001284587cb90c7693ac0e6f3b Also, if age is the #1 factor then Japan should have the worst covid as they have the most old people per capita but they don't. They also haven't locked down but they have worn mask…

Japan is kind-of locked down, mostly by canceling large events and keeping people home. They're working on the principle that covid has mainly aerosol transmission and is spread by rare superspreaders rather than just everyone. It's working okay but not as well as Korea.

Japan isn't keeping people home. Restaurants are open (till 8pm). People are commuting in crowded trains, etc... I walk by the restaurants and cafes and they're plenty busy.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#360

Post by asabjorn » Fri, May 21, 2021, 6:13 PM UTC

dragonwriter wrote: post #353

asabjorn wrote: post #348

Earlier quoted context omitted.

NY (not NYC) cumulative cases is 2m and population is 19.4m, so about 10.3% of population [source: google coronavius stats]. > California 3.7M cumulative cases & 1,336 case/day current 7-day average vs. 39.5M population Its 3.77M, so about 9.5% of population. > Texas 2.9M cumulative case & 2,034 case/day current 7-day average vs. 29M population. That's 10%. > Florida 2.3M cumulative cases & 3,007 case/day 7-day avera…

> With the total cases being about the same so this does not support your conclusion I didn’t offer any conclusion except that the upthread claim that California had a much higher rate of COVID cases than FL/TX was bunk. To actually tease out the effects of mask use from jurisdictional case statistics, you’d also have to (1) have stats on mask use, which (despite people making claims about it in coordination with bla…

>To actually tease out the effects of mask use from jurisdictional case statistics, you’d also have to (1) have stats on mask use, which (despite people making claims about it in coordination with blatantly false claims about cases), I haven’t seen, and (2) have good stats for the other things that would reasonably be expected to contribute to differences in infection spread, (3) either have enough a priori knowledge of the contribution of the items in 2 to control for their effect in 1:1 comparisons, or have data from enough different places to do an analysis that determines the contributions of different factors.

Absolutely, 100% with you. And effectiveness of a mitigation should be determined before mandating it, and the positives and negatives of the mitigation should be well understood.

> I didn’t offer any conclusion except that the upthread claim that California had a much higher rate of COVID cases than FL/TX was bunk.

I was responding to the parents claim that masks “ drastically reduce the spread” which I think I’ve showed is an unsupported claim, although I stated my initial claim too strongly. There is no significant observable effect on state covid case count or state death to confirmed case count (which would to some degree control for some differences in testing).

> Even with good mask stats, a head to head comparison of a couple states case numbers with mask stats wouldn’t otherwise be useful for anything.

After one year of mandating this mitigation we should be able to see some observable difference to continue mandating that people cover their faces. This is not zero-cost, especially for the ones living alone, as the masks block facial expressions showing emotion and the masks make it harder to breathe which can on aggregate cause health issues. For instance, a large number of dental issues is caused by mask use [1].

[1] https://fineartsdentistry.com/how-face-masks-are-affecting-o...