6 ms·

The primary point isn't wrong, but I am deeply deeply deeply skeptical of this, since the underlying data is of such varying and often miserable quality. A frie

by nkoren 7y ago

The primary point isn't wrong, but I am deeply deeply deeply skeptical of this, since the underlying data is of such varying and often miserable quality. A friend of mine in Oregon exhibited all the C19 symptoms, and went to get tested. It took 15 DAYS for her sample to be tested. The test came back negative, but the lab said they had no confidence in this result, given the age of the sample. This is apparently the default testing situation in Oregon. Given those kind of inputs, how can one say with any confidence when Oregon will peak, and how large that peak will be? Other states have much better testing and thus can be more confident in their predictions. Some have worse. For most, however, I get the impression that this kind of modelling is somewhere between a wild-assed guess and a crapshoot.

michaelangerman 7y ago
Number of new cases in Oregon is flat to slightly down in the past six days... 3/25 57 3/26 50 3/27 98 3/28 65 3/29 69 3/30 58 These are new case numbers. Data source: https://weather.com/coronavirus/l/3e056a178cd9fcb8c8efaa5819628301d34eabda3e6903a3f4fd182a62e7b74f https://weather.com/coronavirus/l/3e056a178cd9fcb8c8efaa5819... weather.com case numbers for oregon
- jmull 7y ago
  I think the point is if testing is tightly constrained you can't know much about how many cases you really have. We'd actually want some kind of randomized survey testing in an area to understand the prevalence there, and do it over time to understand the arc, but we aren't doing that -- we still can't test all the people who have a need for am immediate test.
  - cjhopman 7y ago
    Testing is not that constrained. Here you can see stats for both positive and negative: https://covidtracking.com/data/state/oregon/ https://covidtracking.com/data/state/oregon/ Oregon is doing roughly 1400 tests/day, with ~5% positive rate. Places that are more testing constrained see 20+% positive.
threatofrain 7y ago
Testing will also peak out at the state's capacity to test, whereas people will have a hard time hiding dead bodies, so I think some numbers are better for forming a stable picture.
fermienrico 7y ago
They should be using death rates to estimate the peak, not confirmed cases. Death counts are very accurate if not perfect representation of the situation.
- xyzzy_plugh 7y ago
  They're not. For a variety of reasons, many deaths are not being reported as caused by Covid-19, but rather other preexisting conditions which may have been complicated by Covid-19. Additionally, as I understand it, some number of deaths require post-mortem testing to confirm that the victim was indeed infected. Given the varied backlog of testing, the morgue backlog (or soon-to-be) and the lack of testing kits, I'd conservatively expect death counts to be lower than actual by anywhere from 10% to 150%. I wouldn't be surprised if a year from now we realize we were off by a factor of 2 or more.
  - thebruce87m 7y ago
    You can compare normal death rates from previous years to determine if you are having excess deaths. Here is data from a town in Italy for example: https://www.corriere.it/politica/20_marzo_26/the-real-death-toll-for-covid-19-is-at-least-4-times-the-official-numbers-b5af0edc-6eeb-11ea-925b-a0c3cdbe1130.shtml https://www.corriere.it/politica/20_marzo_26/the-real-death-... “Nembro, one of the municipalities most affected by Covid-19, should have had - under normal conditions - about 35 deaths. 158 people were registered dead this year by the municipal offices. But the number of deaths officially attributed to Covid-19 is 31” There are some caveats with the data of course - I.e. the town might not have any more deaths for the rest of the year since it’s burned through all the people that would have expired anyway, but it’s interesting reading.
    - thu2111 7y ago
      The Corriere article has a major flaw that it's looking at deaths from Jan onwards only. This year is unusual in that there was no flu season, really. Deaths up until the start of COVID-19 were way lower than normal all winter. https://swprs.files.wordpress.com/2020/03/italia-mortalita-marzo-14.png?w=1200&h=686 https://swprs.files.wordpress.com/2020/03/italia-mortalita-m... So even a disease no worse than flu, you'd expect would cause a much higher death rate than normal for this time of year, simply by shifting the curve forward six months. And COVID-19 is likely to be worse than flu. (I say likely because the data quality here is so poor we really have no idea how dangerous it is)
bengebre 7y ago
15 days ago was a different universe of testing capacity. Oregon had done less than 500 tests then and was still using the initial (semi-flawed) CDC tests. We've done almost 13,000 tests since then (I live in Oregon). Not to say we're doing enough yet, but it is a totally different situation today in Oregon and elsewhere: https://www.deptofnumbers.com/covid19/oregon/ https://www.deptofnumbers.com/covid19/oregon/ edit: that link is to a site I built to track testing capacity and new case growth.
nod 7y ago
These IHME predictions are actually based on deaths, not on tests. Also, please look at the wide error bars on the original data source: https://covid19.healthdata.org/projections https://covid19.healthdata.org/projections Of course there are still a lot of variables - one of the better criticisms is that it assumes that states lock down with the same strength, just at different dates. But it's the presentation of this Axios piece that is dangerous here: It strips out all the uncertainty estimates and presents exact numbers as if they were precise.

by nkoren 7y ago

michaelangerman 7y ago

Number of new cases in Oregon is flat to slightly down in the past six days... 3/25 57 3/26 50 3/27 98 3/28 65 3/29 69 3/30 58 These are new case numbers. Data source: https://weather.com/coronavirus/l/3e056a178cd9fcb8c8efaa5819628301d34eabda3e6903a3f4fd182a62e7b74f https://weather.com/coronavirus/l/3e056a178cd9fcb8c8efaa5819... weather.com case numbers for oregon

jmull 7y ago
I think the point is if testing is tightly constrained you can't know much about how many cases you really have. We'd actually want some kind of randomized survey testing in an area to understand the prevalence there, and do it over time to understand the arc, but we aren't doing that -- we still can't test all the people who have a need for am immediate test.
- cjhopman 7y ago
  Testing is not that constrained. Here you can see stats for both positive and negative: https://covidtracking.com/data/state/oregon/ https://covidtracking.com/data/state/oregon/ Oregon is doing roughly 1400 tests/day, with ~5% positive rate. Places that are more testing constrained see 20+% positive.

threatofrain 7y ago

Testing will also peak out at the state's capacity to test, whereas people will have a hard time hiding dead bodies, so I think some numbers are better for forming a stable picture.

fermienrico 7y ago

They should be using death rates to estimate the peak, not confirmed cases. Death counts are very accurate if not perfect representation of the situation.

xyzzy_plugh 7y ago
They're not. For a variety of reasons, many deaths are not being reported as caused by Covid-19, but rather other preexisting conditions which may have been complicated by Covid-19. Additionally, as I understand it, some number of deaths require post-mortem testing to confirm that the victim was indeed infected. Given the varied backlog of testing, the morgue backlog (or soon-to-be) and the lack of testing kits, I'd conservatively expect death counts to be lower than actual by anywhere from 10% to 150%. I wouldn't be surprised if a year from now we realize we were off by a factor of 2 or more.
- thebruce87m 7y ago
  You can compare normal death rates from previous years to determine if you are having excess deaths. Here is data from a town in Italy for example: https://www.corriere.it/politica/20_marzo_26/the-real-death-toll-for-covid-19-is-at-least-4-times-the-official-numbers-b5af0edc-6eeb-11ea-925b-a0c3cdbe1130.shtml https://www.corriere.it/politica/20_marzo_26/the-real-death-... “Nembro, one of the municipalities most affected by Covid-19, should have had - under normal conditions - about 35 deaths. 158 people were registered dead this year by the municipal offices. But the number of deaths officially attributed to Covid-19 is 31” There are some caveats with the data of course - I.e. the town might not have any more deaths for the rest of the year since it’s burned through all the people that would have expired anyway, but it’s interesting reading.
  - thu2111 7y ago
    The Corriere article has a major flaw that it's looking at deaths from Jan onwards only. This year is unusual in that there was no flu season, really. Deaths up until the start of COVID-19 were way lower than normal all winter. https://swprs.files.wordpress.com/2020/03/italia-mortalita-marzo-14.png?w=1200&h=686 https://swprs.files.wordpress.com/2020/03/italia-mortalita-m... So even a disease no worse than flu, you'd expect would cause a much higher death rate than normal for this time of year, simply by shifting the curve forward six months. And COVID-19 is likely to be worse than flu. (I say likely because the data quality here is so poor we really have no idea how dangerous it is)

bengebre 7y ago

15 days ago was a different universe of testing capacity. Oregon had done less than 500 tests then and was still using the initial (semi-flawed) CDC tests. We've done almost 13,000 tests since then (I live in Oregon). Not to say we're doing enough yet, but it is a totally different situation today in Oregon and elsewhere: https://www.deptofnumbers.com/covid19/oregon/ https://www.deptofnumbers.com/covid19/oregon/ edit: that link is to a site I built to track testing capacity and new case growth.

nod 7y ago

These IHME predictions are actually based on deaths, not on tests. Also, please look at the wide error bars on the original data source: https://covid19.healthdata.org/projections https://covid19.healthdata.org/projections Of course there are still a lot of variables - one of the better criticisms is that it assumes that states lock down with the same strength, just at different dates. But it's the presentation of this Axios piece that is dangerous here: It strips out all the uncertainty estimates and presents exact numbers as if they were precise.