Author Topic: Coronavirus  (Read 45181 times)

Caracal

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Re: Coronavirus
« Reply #990 on: August 26, 2020, 11:45:17 AM »
I

On a separate note, the apparent death rate has fallen globally, as well as in the US and in other individual countries. Does anyone have any idea why this is? More testing leading to more mild/asymptomatic cases being detected? Hospitals becoming better at keeping people alive? Milder strains of corona becoming dominant?

A lot of it is more cases being identified. In March/April New York City had a positivity rate of almost 50 percent. Mostly, only really sick people were being tested. If you look at cases per capita, New York is 8th, but clearly the outbreak was worse there and in New Jersey than in any other state. Of course, deaths are a lagging indicator. For a while, case counts were going up here without deaths rising too. Unfortunately, probably the death rate will grow in Spain and other places.

spork

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Re: Coronavirus
« Reply #991 on: September 16, 2020, 05:35:19 AM »
NBER paper: effect on non-pharmaceutical interventions in reducing Covid-19 transmission is overstated.

As often happens, the statistical modeling jargon in this economics paper is too dense for me to understand. Can anyone comment knowledgeably about this? I see the authors making these claims, and I offer possible rebuttals to two of them:

First claim: R(t) fell because of a slowdown in transmission rather than development of herd immunity. Seems intuitively obvious.

Second claim: Transmission rates fell all over the world regardless of what NPIs were implemented in various locations, so NPIs probably weren't the cause of the lower transmission rates. Hmmm. Maybe there are many different types of NPIs that reduce transmission, so it really doesn't matter which ones are used, as long as some are used.

Third claim: after the initial case surge and decline, transmission rates remained low after NPIs were lifted, again suggesting NPIs didn't have an effect on reducing the transmission rate. I guess that depends on who was initially getting infected and why. A contagious disease always kills the weakest members of the herd first. Or people in high-risk environments learned how to lessen the chance of infection in ways that the authors of this article aren't modeling.

The authors seem to be focusing mainly on the rate of change in the growth rate of Covid-19 deaths. Maybe I'm misreading this. But the case fatality rate does not go to zero. SARS-CoV-2 is now part of the ecosystem, and given the CFR data I've seen, Covid-19 is ~ 5 times more deadly than influenza. So an NPI as inexpensive as mask-wearing would seem to make economic sense, even if it has only a small effect on reducing transmission of Covid-19 and other airborne pathogens like influenza.


pigou

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Re: Coronavirus
« Reply #992 on: September 16, 2020, 05:59:52 AM »
The finding is pretty similar to another recent paper that found the lockdowns in the US had basically no effect on people's mobility (as measured using cell phone location data). What they found was that once the first local deaths happened, people stopped going out irrespective of whether there was a lockdown. My own observation matched the flipside of this, too: once restaurants here could open again, they were empty for a couple weeks still. And while gyms are again open, just looking at the availability of some of the group fitness classes I used to go to shows that extremely few people are attending (say 4-5 people down from 20-30). Suggests that people have a pretty good sense of how risky things are and they respond (rationally) to local events, not to those happening across the country.

Edit: adding to that, mask mandates in outdoor spaces probably make very little sense. I've seen people wear masks while they are out hiking, which is just absurd. The rules governing restaurants are not very sensible either: people can take off their masks while eating indoors, but they have to put them on to walk to the bathroom. That's just not how air circulation in an indoor space is going to work: the AC blasting is going to be a much bigger problem. Mask mandates in small, enclosed spaces make a lot of sense -- but people are also starting to avoid those. For example, ridership on public transit is *way* down. When I see busses pass by, they're either completely empty or have 2-3 people in them, when they used to be full.

Then we have data like these on Covid accumulation in cars -- something as simple as cracking open the window has a huge effect, whereas it's not clear to me how masks would prevent concentration in the air: https://www.usatoday.com/story/opinion/2020/04/22/coronavirus-car-protect-yourself-column/5166146002/
« Last Edit: September 16, 2020, 06:05:20 AM by pigou »

Caracal

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Re: Coronavirus
« Reply #993 on: September 16, 2020, 06:47:19 AM »


Edit: adding to that, mask mandates in outdoor spaces probably make very little sense. I've seen people wear masks while they are out hiking, which is just absurd. The rules governing restaurants are not very sensible either: people can take off their masks while eating indoors, but they have to put them on to walk to the bathroom. That's just not how air circulation in an indoor space is going to work: the AC blasting is going to be a much bigger problem. Mask mandates in small, enclosed spaces make a lot of sense -- but people are also starting to avoid those. For example, ridership on public transit is *way* down. When I see busses pass by, they're either completely empty or have 2-3 people in them, when they used to be full.



I think it makes sense if you're talking about fairly crowded spaces, especially if it is a business district where people might be walking around and then going in to shops. Ditto for college campuses. The actual risk outdoors is probably pretty low, but I think it creates a cultural expectation around mask wearing that translates into the indoor spaces. Completely agree about restaurants and hiking. On one hand there's this tendency to have rules that can give people a false sense of security in places that are just dangerous. On the other hand, you see an obsession with having weirdly strict rules in places that are pretty low risk, like beaches. Honolulu seems to have a rule that nobody is allowed to be outside on beaches, even just walking, in groups of more than one. There's no exception for family units. Why would you want to discourage families from walking on a beach?

FishProf

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Re: Coronavirus
« Reply #994 on: September 16, 2020, 01:01:16 PM »
In Hawaii, everyone is Ohana.  You'd have massive crowds.

(That's an exaggeration, but only a little)
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spork

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Re: Coronavirus
« Reply #995 on: September 18, 2020, 05:10:38 AM »

polly_mer

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Re: Coronavirus
« Reply #996 on: September 19, 2020, 05:57:25 AM »
The science media giant Nature puts out a daily briefing on science news that might be of interest to this crowd: https://www.nature.com/nature/articles?type=nature-briefing


Edit: adding to that, mask mandates in outdoor spaces probably make very little sense. I've seen people wear masks while they are out hiking, which is just absurd.

It may be absurd on vacant trails.  However, here, the trails are often packed on a nice day.  On a calm enough day, you can smell clouds of BO, sunscreen, and mosquito repellent as you walk.  You'll pass close by dozens of people walking the other way with more crowds on a nice weekend/holiday than you get walking on our sidewalks downtown on random business days.  Yeah, walking outside is lower risk than eating inside at a restaurant, but that 'probably' in your post isn't a 'definitely'.
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Treehugger

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Re: Coronavirus
« Reply #997 on: September 19, 2020, 06:08:16 PM »
Fellow nerds, rejoice! There is some speculation that wearing glasses is protective against the virus.

aside

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Re: Coronavirus
« Reply #998 on: September 19, 2020, 06:10:18 PM »
Fellow nerds, rejoice! There is some speculation that wearing glasses is protective against the virus.

So is the social isolation that often accompanies nerdiness.

evil_physics_witchcraft

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Re: Coronavirus
« Reply #999 on: September 19, 2020, 08:21:33 PM »
Fellow nerds, rejoice! There is some speculation that wearing glasses is protective against the virus.

Are you implying that only nerds wear glasses? :O

dismalist

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Re: Coronavirus
« Reply #1000 on: September 19, 2020, 08:36:49 PM »
We have met the enemy, and they is us.
--Pogo

spork

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Re: Coronavirus
« Reply #1001 on: Today at 05:38:38 AM »
Obesity and Mortality Among Patients Diagnosed With Covid-19

My wife, the doctor, has been telling me that all along, roughly speaking.

So have the physicians that I run with.