IHME COVID-19 Model

[Why_Yes_I_Do]

Originally Posted by friendly fred

Yes, I think social distancing is lowering the infection and death rate - though at this point we know enough about it we should just quarantine anyone over 70 or those with comorbidities, put on masks, and get to work.

Absolutely! Need them young whipper-snappers back in the game propping up those wobbly pension funds and SS. Probably going to take 8 or 9 now to support each retired person. Heave ho, boys and gurls.

[lustylad]

Originally Posted by Tiny

IHME's forecast relies mostly on curve fitting, instead of multiplying population by estimated infection and fatality rates. So their estimates have been a lot lower than most others.

Sorry, I haven't studied up on the methodologies used by any of the forecasters. But pray tell, how the fuck can anyone come up with accurate estimates of "infection and fatality rates" at this point?

We don't have a clue what the national infection rate is. We've tested around 2 million people out of 330 million, which is a mere 0.6%. And those test results are biased upward since we are prioritizing the available tests for sick people and health care workers.

What follows from this is as obvious as night follows day. If we don't have a clue what the infection rate is, then we can't calculate, let alone forecast, the fatality rate! Yes, we are tracking how many people have died from covid-19, but that's just the numerator. The denominator is unknown - and will remain unknown until we roll out random national testing for the entire US population.

Bottom line - any forecast using "estimated infection and fatality rates" should not be taken seriously.

[dilbert firestorm]

Originally Posted by Missburger

bush already did that when he inherited a suprlus from clinton and turned into this huge deficit we have

how quickly you forget

Originally Posted by Missburger

the economy under clinton was growing and much better than now would you like to get some graphs out to show the gnp and other stats to compare

we had a surplus under bill balanced the budget,

there never was a surplus. that was a lie in the form of smoke and mirrors!!!!

[nevergaveitathought]

Originally Posted by lustylad

Bottom line - any forecast using "estimated infection and fatality rates" should not be taken seriously.

you mean treat it just as one should a forecast by the nobel memorial prize for economic sciences winner paul krugman?

[oeb11]

+1 - the Nobel committee screwed up that one.

[Tiny]

Originally Posted by lustylad

Bottom line - any forecast using "estimated infection and fatality rates" should not be taken seriously.

Well yeah, it has turned out that way hasn't it. Initially people only had data from China, which was suspect. And the Chinese were mostly testing people with symptoms. The first decent indication came from the Diamond Princess cruise ship. Oeb has linked to this. There were 3711 people on board and 700 were infected. Three thousand were tested. So far eight have died. The people on the cruise ship were older than average. Epidemiologists took the fatality rate of a little over 1% and some adjusted this downward for the general population.

As to infection rate, you can't really extrapolate from a cruise ship to the general public. Epidemiologists try to come up with a number they call "R naught", or Ro, being the average number of people infected by a carrier, from testing and tracing. That number is believed to have initially been about 3.5. One person who's infected will in turn infect 3.5 people on average. The number has gone down as people have practiced social distancing, and maybe as some have developed "herd immunity". When Ro goes below 1 and stays below 1 the disease stops spreading and dies out. It should go below 1 when 50% to 75% of the population has had the disease, because of herd immunity. It will go below 1 if everyone shuts themselves away and no one goes out in public, at least as long as they stay shut in.

The infection rate of the population will depend on how Ro changes over time. Predicting changes in Ro must be very difficult, especially when you don't have much testing. Therefore estimating fatalities from the infection rate and the fatality rate are difficult. Epidemiologists came up with everything from 10,000 deaths (low example described in article Oeb linked to) to 2,000,000 deaths (Imperial College estimate, assuming no social distancing, which scared the crap out of people.)

Using historical data like IHME and curve fitting makes a lot more sense, once you've got that data. People can criticize them for dropping their initial estimate from 81,000 deaths to 60,000 now, but either number will be a lot closer to the truth than 2,000,000 deaths.

[oeb11]

A fiasco in the making? As the coronavirus pandemic takes hold, we are making decisions without reliable data


By John P.A. Ioannidis
March 17, 2020
https://www.statnews.com/2020/03/17/...reliable-data/


Tiny - well written, good sir. Good explanation of epidemiologic statistical tools.

Link above - i still have sen nothing to improve on the article.



Wuhan virus is looking more and more like as behaving as Influenza A.

yes, NYC seems affected - but their population density and manner of life - crowded with millions of people in high density high rises, packed transportation, and working in jammed high rises - predisposes to virus droplet transmission .


Interesting - NY'ers tend to walk more - and my impression is a lower incidence of obesity. does not seem to positively affect the people as far as wuhan virus - but once this is over - better epidemiologic data will be analyzed and we will see.

as compared to Texas where folks live in homes with yards, separated, commute to work, and live a much more separate lifestyle. Virus transmission is more difficult.

[friendly fred]

Mollie
@MZHemingway
·
6h
IMHE projections for Virginia dropped today to 891 deaths, needing 319 ICU beds, and needing 272 ventilators. A week ago, IMHE had projected 3,073 deaths, needing 918 beds, and needing 734 ventilators. Both projections assume(d) "full social distancing" through May.

[Why_Yes_I_Do]

Originally Posted by nevergaveitathought

you mean treat it just as one should a forecast by the nobel memorial prize for economic sciences winner paul krugman?

Remember when the Ovomit-Comet got one from them?

[Why_Yes_I_Do]

Originally Posted by oeb11

...as compared to Texas where folks live in homes with yards, separated, commute to work, and live a much more separate lifestyle. Virus transmission is more difficult.

Hey! Ya wanna keep that down over there? I've been telling the more dorkus neighbors "social distance" otherwise I would chat across the fence with them. Just smile and wave boys.

[SpeedRacerXXX]

Originally Posted by oeb11

[B]

as compared to Texas where folks live in homes with yards, separated, commute to work, and live a much more separate lifestyle. Virus transmission is more difficult.

Very true. But once people get to work, for those who are still at work these days, the risk of infection is higher. This is Trump's dilemma -- if he supports people returning to work and the virus stops spreading, he wins. But if the virus starts up again, he loses.

You may have even asked the question before. When will it be considered safe to get the workforce back to work?

[lustylad]

Originally Posted by Tiny

Well yeah, it has turned out that way hasn't it. Initially people only had data from China, which was suspect. And the Chinese were mostly testing people with symptoms. The first decent indication came from the Diamond Princess cruise ship. Oeb has linked to this. There were 3711 people on board and 700 were infected. Three thousand were tested. So far eight have died. The people on the cruise ship were older than average. Epidemiologists took the fatality rate of a little over 1% and some adjusted this downward for the general population.

As to infection rate, you can't really extrapolate from a cruise ship to the general public. Epidemiologists try to come up with a number they call "R naught", or Ro, being the average number of people infected by a carrier, from testing and tracing. That number is believed to have initially been about 3.5. One person who's infected will in turn infect 3.5 people on average. The number has gone down as people have practiced social distancing, and maybe as some have developed "herd immunity". When Ro goes below 1 and stays below 1 the disease stops spreading and dies out. It should go below 1 when 50% to 75% of the population has had the disease, because of herd immunity. It will go below 1 if everyone shuts themselves away and no one goes out in public, at least as long as they stay shut in.

The infection rate of the population will depend on how Ro changes over time. Predicting changes in Ro must be very difficult, especially when you don't have much testing. Therefore estimating fatalities from the infection rate and the fatality rate are difficult. Epidemiologists came up with everything from 10,000 deaths (low example described in article Oeb linked to) to 2,000,000 deaths (Imperial College estimate, assuming no social distancing, which scared the crap out of people.)

Using historical data like IHME and curve fitting makes a lot more sense, once you've got that data. People can criticize them for dropping their initial estimate from 81,000 deaths to 60,000 now, but either number will be a lot closer to the truth than 2,000,000 deaths.

Good post. You're evidently following this more closely than I am. I interpreted "infection rate" to mean the percentage of the general population that either has or had the virus at any given moment. The other meaning, which appears to be driving the various models, is the rate at which the virus is spreading. Obviously social distancing and stay-at-home edicts can have a dramatic impact on the latter.

[Tiny]

Originally Posted by lustylad

Good post. You're evidently following this more closely than I am. I interpreted "infection rate" to mean the percentage of the general population that either has or had the virus at any given moment. The other meaning, which appears to be driving the various models, is the rate at which the virus is spreading. Obviously social distancing and stay-at-home edicts can have a dramatic impact on the latter.

I'm hesitant to disclose personal info including occupation here. If somebody in my community finds out I'm posting on a hooker board then all the free poontang I've been getting from the church widows goes up in smoke. But if you do what I do, you've probably become an amateur epidemiologist. When I ran across the IHME estimate of just 80,000 deaths I was excited. I was factoring the possibility of a few hundred thousand deaths into decisions. IHME was using actual recent histories of deaths and hospitalizations from the new coronavirus for their forecasts, instead of assumptions for numbers like infection rate and fatality rate which could vary by a factor of ten. So I became a lot more optimistic about this. And ended up with a very different opinion of IHME than Fred and some other posters.

[oeb11]

SR - But once people get to work, for those who are still at work these days, the risk of infection is highee


An assumption on Ur part - SR - possible the risk is higher for those in Texas still working.

What is the relative risk v NYC - IMHO - no data to support my opinion - still lower risk in Texas than NYC
If Sr has data/proof - I would like to see it.

O/W just Opinion.

[SpeedRacerXXX]

Originally Posted by oeb11

SR - But once people get to work, for those who are still at work these days, the risk of infection is higher

And that is Trump's dilemma. Yes, the risk of infection is higher when more people return to work. Governors actually have the say as to removing work restrictions but Trump will push them if he believes the time has come. If people return to work and the coronavirus curve takes off again, bad news for Trump. If the curve stays on the decline, good news.