Coronavirus: About Those IHME Projections…

 

As most of you know, the Institute for Health Metrics and Evaluation (IHME) at the University of Washington has published a series of COVID-19 projections over the past couple of weeks. The IHME projections are sometimes called the “Chris Murray” model, after its director. It appears that these projections are being widely used by the Trump administration and other government officials. The main site is here.

The IHME released its original projections on March 26, and has released updates on March 30 and 31 and April 1, 2, 5, and 7. It appears that only the most recent projection is available for download at the site. From previous downloads, I have all of them except April 1 (which appears quite similar to April 2, based on the update notes that are available for each update here).

This post is an evaluation of the changes in the IHME projections. I focus on two issues: (1) estimated deaths in the US, and (2) estimated ICU bed requirements in the US.

I. IHME’s death projections are highly variable.

I focus on the March 26 and the April 2, 5, and 7 IHME projections of US COVID-19 deaths. The March 30-31 projections appear quite similar to March 26, and the April 1 update appears quite similar to April 2.

Here is a graph of projected daily deaths:

The first projection on March 26 (yellow) and the latest on April 7 (green) look quite similar, though they are not because the decline in the April 7 update is much faster. (This will be more evident in the next graph.) The April 2 update was a notable increase from March 26, and the April 5 update included a higher spike even than April 2, though it is also a shorter spike.

Here is the graph of projected cumulative deaths:

Here you can see the endpoint of each projection. The original March 26 projection (yellow) predicted 81,114 total deaths. This increased with the April 2 update (red), to 93,531. The April 5 update (blue) declined significantly (12.5%) to 81,766, though you can see the effect of the sharper spike in projected daily deaths in the more rapid increase in the blue line. The April 7 update (green) was a further significant decline (26.1%) to 60,415.

The total decline in projected deaths between the April 2 and the April 7 projection was over 35%. That’s a remarkably large change in a matter of five days.

The projections were quite wildly variable between states. A few examples:

  • Massachusetts, which is currently projected to have the second-highest death total, changed from 2,382 in the April 2 update, to 8,254 in the April 5 update, to 5,625 in the April 7 update.
  • New Jersey, which is currently projected to have the third-highest death total, changed from 2,117 in the April 2 update, to 9,691 in the April 5 update, to 5,277 in the April 7 update.

I’m not going to report the state subtotals, because they seem to be quite unreliable.

II. IHME’s ICU bed projections are highly variable and unreliable.

Another major feature of the IHME’s projections is the estimate of ICU bed requirements and shortfalls. They do a similar projection for overall hospital beds, but I’m going to focus on the ICU projections.

Here is the graph of the estimated number of ICU beds required for COVID-19 patients in the US:

You can see the large figure in the original March 26 projection (yellow), which increased in the April 2 update (red). Remember that the April 2 update was less than a week ago. The March 26 projection had a peak of 36,076 ICU beds on April 10, and the April 2 update increased this to a peak of 40,646 on April 12.

Both of the latest two updates have been significant declines. The April 5 update had a peak of 29,417 on April 16. Through this point, the projections had predicted a later date of peak ICU requirements. This changed with the April 7 update yesterday, which peaks at just 19,905 ICU beds on April 14.

Thus, projected ICU bed requirements dropped by more than 50% over the five days between the April 2 and the April 7 updates.

An even more important estimate presented by IHME is the projected shortage in ICU beds. This is the projection of the number of Americans that, according to IHME, would require ICU care but would be unable to receive such care. It is probably the most important single projection in the model, as a practical matter. Here is the graph::

You can see that the IHME predicted in its first release, on March 26 (yellow), that 17,380 Americans would be unable to obtain necessary ICU care on the peak date (which was then projected to be tomorrow, April 9). This estimate increased dramatically in the April 2 update (red) to 22,382 (to occur on April 10). The projection decreased and moved further into the future with the April 5 update (blue) to 16,433 (to occur on April 16).

The estimate decreased again with the April 7 update (green) to 9,047, predicted to occur on April 11. Thus, this prediction declined by about 60% over the five days between the April 2 and the April 7 updates.

It gets worse.

The IHME projections include a detailed projection for each individual state, day by day, which are totaled to create the nationwide figures cited above. I wondered whether the projected ICU shortage was heavily concentrated in certain states. It turns out that it is — New York and New Jersey. This should not be a surprise, because these two states have the highest number of reported deaths thus far.

The data allows me to determine the total number of available ICU beds in NY and NJ, according to the IHME projections. These figures are 718 for NY and 465 for NJ, a total of 1,183 available ICU beds in these two states combined.

I happen to have looked up information on the ICU shortage yesterday. According to this NYT article, New York state had 4,593 COVID-19 patients in the ICU yesterday (Tuesday, April 7), and New Jersey had 1,651. This was up slightly from 4,504 in NY and 1,505 in NJ on Monday, April 6.

The April 7 reported total for these two states, of COVID-19 patients actually in the ICU, was 6,244. Which is quite remarkable, since according to the IHME report released that same day, there would only be 1,183 ICU beds available to such patients.

Here is a graph of the projected need for ICU beds from the IHME updates on April 2 and April 7, showing the nationwide total and the total for just NY and NJ:

The red lines show the projected need for ICU beds in the April 2 update, for the entire US (top red line) and for just NY and NJ (lower red line). The green lines show the same projection in the April 7 update. The blue line is IHME’s estimate of total available ICU beds in NY and NJ. You can see that both of the lower lines (red and green) are far above the blue line. So much for “flattening the curve.”

Except, notice that highlighted yellow line (which actually connects two points). That is the actual number of COVID-19 patients in the ICU, in NY and NJ, on the past two days (April 6-7). Notice how it is vastly above the blue line, which is the number of available ICU beds assumed in the IHME model.

So I performed my own calculation on IHME’s projection of the shortage in ICU beds. They were obviously wrong about NY and NJ. What I did was to assume that, contrary to their model, there were 6,244 available ICU beds in NY and NJ for COVID-19 patients — not just 1,183 as assumed by IHME — which seems quite plausible in light of the NYT report that 6,244 COVID-19 patients were actually in the ICU in these two states yesterday.

Here’s how the ICU bed shortage graph looks, with my adjustment:

The red lines are the IHME’s projected shortage of ICU beds from its April 2 update, for the entire country and for just NY and NJ. The green lines are the same thing from the April 7 update. Note that in the April 7 update, most of the projected national shortage in ICU beds was in NY and NJ. Except, as noted above, there was no shortage in ICU beds in NY and NJ yesterday (April 7), according to the NYT.

The yellow lines are my calculations. What I did was to adjust IHME’s April 7 projection of the ICU bed shortage downward, as we know that at least 5,061 additional available ICU beds in NY and NJ (5,061 is the difference between ICU beds in NY and NJ actually occupied yesterday, 6,244, and the IHME’s assumption that only 1,183 ICU beds are available in these states).

You will notice that this one assumption virtually eliminates the projection for the ICU bed shortage. My top yellow line, the national projection, makes a “hump” because I did not adjust IHME’s assumptions for available ICU beds in other states (as I lack information to do so at this time). My calculation was not a blanket reduction of the national ICU shortage projection by 5,061 — rather, I reduced IHME’s April 7 projection (the top green line to my top yellow line) by the lesser of 5,061 or the number of ICU beds occupied in IHME’s projection for NY and NJ.

The lower yellow line — my adjusted estimate for NY and NJ — assumes that IHME’s projection of ICU beds needed in NY and NJ is accurate, and assumes that their ICU beds were fully occupied yesterday. I strongly suspect that this will not be the case.

My suspicion is that the actual shortage in ICU beds is zero, and should be zero in IHME’s projection. In my adjusted calculation, the peak ICU bed shortage in NY and NJ occurs tomorrow (April 9), at a shortage of 1,869 ICU beds. Of course, it is possible that the COVID-19 epidemic will exceed IHME’s latest projections, in which case it there might be a shortage of ICU beds.

Due to these deficiencies, I have concluded that IHME’s projection of ICU bed shortage is not only highly variable but is unreliable. It appears to be based upon a significant underestimate of total ICU bed availability.

I would like to be able to include a line in the graphs above for total nationwide ICU bed availability. This is not feasible from the information in the IHME model, as they do not report this figure directly. Rather, for some states, I can calculate their assumption regarding ICU bed availability as the difference between their projected ICU bed need and shortage. For many states, however, there is no shortage in the model, so I cannot calculate IHME’s assumed number of ICU beds in such states. Such a calculation would not be particularly helpful in any event, because ICU bed availability is a local issue — if you need an ICU bed in New Jersey, and there’s a bed available in Idaho, it doesn’t actually help.

III. Other issues with the IHME model

Two days ago, I posted my Deep Dive into the IHME model. I was particularly concerned that they appeared to have adjusted the model such that their “social distancing” measures no longer affected their estimated number of deaths, though it appeared that “social distancing” did affect the timing of such deaths. This occurred in a significant change in the IHME model released on April 5, and the update notes were ambiguous, so what they had done was unclear.

The April 5 update notes (here) stated that “more detailed information in the form of technical appendices will be published online by Tuesday, April 7,” and gave a link. It is now Wednesday afternoon, April 8, and the promised technical appendices are not available at the linked location, and do not appear to be available anywhere at the IHME site. This is disappointing.

It is also troubling that IHME does not appear to make its prior estimates available for download. It is possible that they are at the site, and I simply failed to find them. Transparency would dictate that they should “show their work,” including making an archive of their prior estimates readily accessible. (They do have such an archive for their update notes, which is good.) As noted at the outset, I had previously downloaded their original projection and all but one of the updates, so I had the information necessary to perform the analysis above.

IV. IMHE’s April 7 update included European totals

I have not analyzed them yet, but I noted that IHME’s April 7 update extended its projections to various European countries. Here is a quick summary for the larger nations of Western Europe.

Italy: IMHE states that Italy’s deaths may have peaked on March 27, and estimates a total of 20,300 in Italy (range 19,533-21,185). My data (from Johns Hopkins) showed Italy at 17,127 yesterday.

Spain: IHME states that Spain’s deaths may have peaked on April 1, and estimates a total of 19,209 in Spain (range 18,049-20,651). My data showed Spain at 14,045 yesterday.

France: IHME states that France’s deaths may have peaked on April 3, and estimates a total of 15,058 in France (range 12,906-17,715). My data showed France at 10,328 yesterday.

UK: IMHE projects the highest number of deaths, by a wide margin, in the UK. Their estimate is 66,314 (range 55,022-79,995). This is higher than their current estimate for the US, even without adjusting for population, and would be the proportional equivalent of about 325,000 deaths in the US. They project a peak in the UK on April 17. My data showed the UK at 6,159 yesterday.

Germany: IHME projects 8,802 deaths in Germany (range 4,253-21,350), with a peak on April 19. My data showed Germany at 2,016 yesterday.

I have not evaluated these estimates. It does seem very strange that IHME predicts such a high figure for the UK.

ChiCom delenda est.

Published in Healthcare
This post was promoted to the Main Feed by a Ricochet Editor at the recommendation of Ricochet members. Like this post? Want to comment? Join Ricochet’s community of conservatives and be part of the conversation. Join Ricochet for Free.

There are 52 comments.

Become a member to join the conversation. Or sign in if you're already a member.
  1. Jack Shepherd Inactive
    Jack Shepherd
    @dnewlander

    They’re still basing their model on the reported figures from China, right? And the variations are just due to changing the inputs based on actual figures in the US?

    • #1
  2. Jerry Giordano (Arizona Patrio… Member
    Jerry Giordano (Arizona Patrio…
    @ArizonaPatriot

    Jack Shepherd (View Comment):

    They’re still basing their model on the reported figures from China, right? And the variations are just due to changing the inputs based on actual figures in the US?

    It seems to be more complicated than this, but without the technical notes to the April 5 update, I can’t tell.  The figures changed significantly on April 5, and it appears that they incorporated adjustments to the model by adding information from 7 additional regions outside China (5 in Italy, 2 in Spain, if I recall correctly).

    This change caused a modest downward revision in the IHME death estimate, but made the spike quite a bit steeper on both sides.  This is consistent with what they said in the April 5 update notes, which was that the peak was passed more quickly in Italy and Spain than in Wuhan.

    Unfortunately, I don’t yet know the details.

    • #2
  3. Jack Shepherd Inactive
    Jack Shepherd
    @dnewlander

    Jerry Giordano (Arizona Patrio… (View Comment):

    Jack Shepherd (View Comment):

    They’re still basing their model on the reported figures from China, right? And the variations are just due to changing the inputs based on actual figures in the US?

    It seems to be more complicated than this, but without the technical notes to the April 5 update, I can’t tell. The figures changed significantly on April 5, and it appears that they incorporated adjustments to the model by adding information from 7 additional regions outside China (5 in Italy, 2 in Spain, if I recall correctly).

    This change caused a modest downward revision in the IHME death estimate, but made the spike quite a bit steeper on both sides. This is consistent with what they said in the April 5 update notes, which was that the peak was passed more quickly in Italy and Spain than in Wuhan.

    Unfortunately, I don’t yet know the details.

    Since I trust the Chinese numbers about as far as I can throw a cow, I have a hard time taking any of these predictions very seriously. Especially as they fluctuate so rapidly and still manage to miss pretty bacly.

    • #3
  4. OldPhil Coolidge
    OldPhil
    @OldPhil

    The April 7 update (green) was a further significant decline (26.1%) to 60,415.

    35,000-45,000. Bookmarket.

    • #4
  5. MISTER BITCOIN Inactive
    MISTER BITCOIN
    @MISTERBITCOIN

    the UK figure is a reckless extrapolation 

    I hate to sound like a broken record: bet the under

     

    • #5
  6. Jerry Giordano (Arizona Patrio… Member
    Jerry Giordano (Arizona Patrio…
    @ArizonaPatriot

    MISTER BITCOIN (View Comment):

    the UK figure is a reckless extrapolation

    I hate to sound like a broken record: bet the under

     

    About the UK, that’s my initial impression, too.

    • #6
  7. MISTER BITCOIN Inactive
    MISTER BITCOIN
    @MISTERBITCOIN

    UK NHS refuses to treat patients with hcq

    that will only increase the body count

    but not 66,666 deaths

     

    • #7
  8. Mendel Inactive
    Mendel
    @Mendel

    These forecasts seem as though they might be less than worthless.

    I do hope (and assume) that many people have been saving the granular predictions after each update, and will trot them out if the actual figures end up falling short. Since the model predicts the peak daily deaths in about a week’s time, significant underperforming of this benchmark would hopefully be a convincing argument to start aggressively thinking about loosening the lockdowns.

    • #8
  9. DonG (skeptic) Coolidge
    DonG (skeptic)
    @DonG

    Jerry Giordano (Arizona Patrio…: Two days ago, I posted my Deep Dive into the IHME model. I was particularly concerned that they appeared to have adjusted the model such that their “social distancing” measures no longer affected their estimated number of deaths, though it appeared that “social distancing” did affect the timing of such deaths.

    Yes and no.  Social separation will lower the R0 from 3.0 to 1.5, which stretches the curve, but also lowers the level at which herd immunity is effective.    1 – 1/R0 is the fraction of population to achieve herd immunity.

    for R0=1.5, herd immunity is 33%

    for R0=3.0, herd immunity is 66%

    Thus distancing should cut the number of infected in half and thus cut the total number of dead by half.

     

    • #9
  10. MISTER BITCOIN Inactive
    MISTER BITCOIN
    @MISTERBITCOIN

    prediction is hard, especially about the future

    check out this blast from the past

    https://www.today.com/video/dr-fauci-on-coronavirus-fears-no-need-to-change-lifestyle-yet-79684677616

    Feb 29

     

    https://saraacarter.com/jan-flashback-dr-fauci-said-coronavirus-is-not-a-major-threat-to-the-people-of-the-united-states/

    “This is not a major threat to the people of the United States and this is not something that the citizens of the United States should be worried about right now,” Dr. Fauci told Newsmax’s Greg Kelly on January 21.

     

    • #10
  11. Jerry Giordano (Arizona Patrio… Member
    Jerry Giordano (Arizona Patrio…
    @ArizonaPatriot

    DonG (skeptic) (View Comment):

    Jerry Giordano (Arizona Patrio…: Two days ago, I posted my Deep Dive into the IHME model. I was particularly concerned that they appeared to have adjusted the model such that their “social distancing” measures no longer affected their estimated number of deaths, though it appeared that “social distancing” did affect the timing of such deaths.

    Yes and no. Social separation will lower the R0 from 3.0 to 1.5, which stretches the curve, but also lowers the level at which herd immunity is effective. 1 – 1/R0 is the fraction of population to achieve herd immunity.

    for R0=1.5, herd immunity is 33%

    for R0=3.0, herd immunity is 66%

    Thus distancing should cut the number of infected in half and thus cut the total number of dead by half.

     

    Don, two responses to this.

    First, I was describing what I think the April 5 update to the IHME model is doing.  It is not a SIR model, so it doesn’t use the R0 analysis.  What I was saying was that social distancing may not change the estimated number of deaths in the IHME model, if they have modified the model as I suspect.

    Second, as I understand the SIR model, it is more complex than you suggest.  Social separation won’t necessarily lower the R0 from 3.0 to 1.5 — it will lower it, but we don’t necessarily know either the starting figure or the lowered figure.  In addition, as I understand it, unless you keep the distancing in place forever, there is a second wave.  In your example, with social distancing, infections are cut in half, and 33% are infected.  But unless the disease is 100% eradicated, when social separation ends, there is no longer herd immunity (because only 33% have been infected previously).  Thus the second wave.  

    • #11
  12. Jack Shepherd Inactive
    Jack Shepherd
    @dnewlander

    MISTER BITCOIN (View Comment):

    prediction is hard, especially about the future

    check out this blast from the past

    https://www.today.com/video/dr-fauci-on-coronavirus-fears-no-need-to-change-lifestyle-yet-79684677616

    Feb 29

     

    https://saraacarter.com/jan-flashback-dr-fauci-said-coronavirus-is-not-a-major-threat-to-the-people-of-the-united-states/

    “This is not a major threat to the people of the United States and this is not something that the citizens of the United States should be worried about right now,” Dr. Fauci told Newsmax’s Greg Kelly on January 21.

     

    Has anyone asked him about those quotes during any of the daily briefings since then, or are all the included media on the “The Sky is Falling, and it’s Trump’s Fault” bandwagon?

    • #12
  13. Lee Member
    Lee
    @user_281935

    Dr. Brix announced at today’s Task Force press conference that today’s IHME numbers (for the mortality curve) included U.S. data for the first time.  Initially only data from China was used, then once the peak in the curve in Italy and Spain was reached (apparently a confirmation that can be used statistically) that data was added last week.  So I would assume that today’s 35% drop reflects the impact to date of social distancing in the U.S.    

    • #13
  14. Jack Shepherd Inactive
    Jack Shepherd
    @dnewlander

    Lee (View Comment):

    Dr. Brix announced at today’s Task Force press conference that today’s IHME numbers (for the mortality curve) included U.S. data for the first time. Initially only data from China was used, then once the peak in the curve in Italy and Spain was reached (apparently a confirmation that can be used statistically) that data was added last week. So I would assume that today’s 35% drop reflects the impact to date of social distancing in the U.S.

    How much panic did they induce by relying on China’s clearly fictitious numbers for so long? Check them out. They’re not real. They match a basic exponential growth pattern too closely, in both cases and deaths, then they just suddenly… stop.

    • #14
  15. Hammer, The Inactive
    Hammer, The
    @RyanM

    Mendel (View Comment):

    These forecasts seem as though they might be less than worthless.

    I do hope (and assume) that many people have been saving the granular predictions after each update, and will trot them out if the actual figures end up falling short. Since the model predicts the peak daily deaths in about a week’s time, significant underperforming of this benchmark would hopefully be a convincing argument to start aggressively thinking about loosening the lockdowns.

    Especially since their projections took into account all of the shutdown measures.  A lot of evidence suggests that the lockdowns are not having any meaningful effect.

    • #15
  16. Hammer, The Inactive
    Hammer, The
    @RyanM

    Lee (View Comment):

    Dr. Brix announced at today’s Task Force press conference that today’s IHME numbers (for the mortality curve) included U.S. data for the first time. Initially only data from China was used, then once the peak in the curve in Italy and Spain was reached (apparently a confirmation that can be used statistically) that data was added last week. So I would assume that today’s 35% drop reflects the impact to date of social distancing in the U.S.

    Their predictions always assumed an impact from social distancing.  The fact that their number have been off by so much is not accounted for by social distancing.  More likely, it suggests that the disease has been with us far longer than we supposed…  which means it probably did its thing before we ever thought to do ours.

    • #16
  17. Jon1979 Inactive
    Jon1979
    @Jon1979

    On the ICU bed discrepancy, I suppose the model could have underestimated the ability of medical personnel in the NY metro area to be able to create new ICU bed space on short notice, so that the numbers in the IHME model were based on previous, but now outdated, information.

    That’s the charitable way to assume the models of the past few weeks were well-intentioned, but misinformed.  The more cynical reading of the April 7 adjustments versus the previous models was that the IHME went with the worst-case scenarios in order to make it more likely the public would follow the safe distancing/shelter-in-place restrictions without protest, but those fears were based on hypothetical numbers that eventually were going to have to turn into real world statistics, in terms of infections, ICU visits, and deaths. As real world underperforms the projections, the projections have to be brought into line with current reality to some extent, or they start looking absurd and people will lose faith in the models faster.

    In a way it’s like Al Gore hanging himself out to dry by not extending his apocalyptic environmental claims out far enough, and claiming environmental models in 2008 showed the polar ice caps would be gone by 2013. That allowed Gore model to break from reality far too fast, and he only avoided being a public laughingtock in part because the big media opted not to call him on it. But his sequel to “An Inconvenient Truth” still bombed at the box office. The new apocalyptic claims avoid that mistake, by pushing the end-of-times models out a decade or more, so that reality doesn’t underperform the hyperbolic claims as quickly.

    • #17
  18. Jerry Giordano (Arizona Patrio… Member
    Jerry Giordano (Arizona Patrio…
    @ArizonaPatriot

    Hammer, The (View Comment):

    Lee (View Comment):

    Dr. Brix announced at today’s Task Force press conference that today’s IHME numbers (for the mortality curve) included U.S. data for the first time. Initially only data from China was used, then once the peak in the curve in Italy and Spain was reached (apparently a confirmation that can be used statistically) that data was added last week. So I would assume that today’s 35% drop reflects the impact to date of social distancing in the U.S.

    Their predictions always assumed an impact from social distancing. The fact that their number have been off by so much is not accounted for by social distancing. More likely, it suggests that the disease has been with us far longer than we supposed… which means it probably did its thing before we ever thought to do ours.

    I want to chime in and agree with The Hammer here.

    Lee, there is no evidence whatsoever that social distancing had any effect on the IHME projection, or that it has had any effect on the actual death rates or case rates.  It may have, and I expect that it would have, but it is not proper reasoning to assume that the social distancing accounts for any changes.

    In fact, it is the opposite of scientific reasoning to make such an assertion.  It is proper to make it as a hypothesis, and then to require actual evidence to demonstrate whether or not the hypothesis is true.  Post hoc ergo propter hoc is not valid scientific reasoning.

    I have been carefully tracking the decline in the rate of increase of reported COVID-19 deaths in the US.  I expected a lag of about 3 weeks before social distancing would have an effect on the death rate.  That should have occurred somewhere around April 1, give or take a few days.  There has been no noticeable change in the graph.

    • #18
  19. Jerry Giordano (Arizona Patrio… Member
    Jerry Giordano (Arizona Patrio…
    @ArizonaPatriot

    Mendel (View Comment):

    These forecasts seem as though they might be less than worthless.

    I do hope (and assume) that many people have been saving the granular predictions after each update, and will trot them out if the actual figures end up falling short. Since the model predicts the peak daily deaths in about a week’s time, significant underperforming of this benchmark would hopefully be a convincing argument to start aggressively thinking about loosening the lockdowns.

    Jon1979 (View Comment):

    On the ICU bed discrepancy, I suppose the model could have underestimated the ability of medical personnel in the NY metro area to be able to create new ICU bed space on short notice, so that the numbers in the IHME model were based on previous, but now outdated, information.

    That’s the charitable way to assume the models of the past few weeks were well-intentioned, but misinformed.

    I think that the projections may have served a useful purpose, by highlighting the need to clear the ICUs to the extent possible, and convert other hospital rooms to ICU-type units.

    But there was waste involved.  RushBabe has a new post about a field hospital built in an event center in Seattle, that was never used and is now being torn down.  I have a comment with details about how the IHME projections probably led to this waste.

    • #19
  20. Mendel Inactive
    Mendel
    @Mendel

    Hammer, The (View Comment):
    Their predictions always assumed an impact from social distancing. The fact that their number have been off by so much is not accounted for by social distancing. More likely, it suggests that the disease has been with us far longer than we supposed… which means it probably did its thing before we ever thought to do ours.

    This is actually the least probable explanation for why the actual numbers are coming in lower than the projections (even the ones including strict social distancing).

    From a scientific perspective, the notion that areas of the US (like WA state) with so few hospitalizations and deaths from Covid-19 have actually been silently infected strains credulity to the breaking point. Moderate-to-severe cases of Covid-19 have a distinct pathology that clearly presents to doctors as something unusual. So the notion that Covid-19 patients were going to the hospital but doctors were misdiagnosing them as having a common respiratory virus are highly unlikely. It is also unlikely that the virus managed to infect a large percentage of the population without sending anyone to the hospital given the throngs of patients seeking medical care in other regions affected by the virus. Furthermore, preliminary data from the hardest-hit town in Germany was released today suggesting that the number of undetected infections was “only” twice as large as the number of infections detected by PCR testing.

    I think the reasons why the actual figures are so much lower than the projections are much more likely to be one of the following: a) the reproduction number of the virus is lower than we think, b) it’s easier to prevent the spread of the disease than the models think, c) the hospitalization/mortality rates in China, Italy, and Spain will turn out to be much higher than in the US due to factors such as more elderly patients, more transmission within hospitals, worse healthcare systems, etc. Remember that most of the original data fed into the IHME algorithm was derived from those countries.

    • #20
  21. D.A. Venters Inactive
    D.A. Venters
    @DAVenters

    Jerry Giordano (Arizona Patrio… (View Comment):

    Hammer, The (View Comment):

    Lee (View Comment):

    Dr. Brix announced at today’s Task Force press conference that today’s IHME numbers (for the mortality curve) included U.S. data for the first time. Initially only data from China was used, then once the peak in the curve in Italy and Spain was reached (apparently a confirmation that can be used statistically) that data was added last week. So I would assume that today’s 35% drop reflects the impact to date of social distancing in the U.S.

    Their predictions always assumed an impact from social distancing. The fact that their number have been off by so much is not accounted for by social distancing. More likely, it suggests that the disease has been with us far longer than we supposed… which means it probably did its thing before we ever thought to do ours.

    I want to chime in and agree with The Hammer here.

    Lee, there is no evidence whatsoever that social distancing had any effect on the IHME projection, or that it has had any effect on the actual death rates or case rates. It may have, and I expect that it would have, but it is not proper reasoning to assume that the social distancing accounts for any changes.

    In fact, it is the opposite of scientific reasoning to make such an assertion. It is proper to make it as a hypothesis, and then to require actual evidence to demonstrate whether or not the hypothesis is true. Post hoc ergo propter hoc is not valid scientific reasoning.

    I have been carefully tracking the decline in the rate of increase of reported COVID-19 deaths in the US. I expected a lag of about 3 weeks before social distancing would have an effect on the death rate. That should have occurred somewhere around April 1, give or take a few days. There has been no noticeable change in the graph.

    It is also possible the projection simply underestimated how effective the social distancing rules and practices would be.  I doubt there was much data out there to give them an idea of exactly what impact those changes would have.  Thankfully, what we’ll never know what the numbers would have been without it.  But if we know that the disease spreads by social contact, then there is no way that the social distancing could fail to have some impact.

    I say maintain the social distancing and stay-at-home orders until mass testing is available and practical, even for asymptomatic people, early detection and effective treatments are out there and available for patients.  From the headlines, those things could be just a few weeks away.  Even then, be prepared to lock down again if there is a spike until a vaccine comes along.

    • #21
  22. Mendel Inactive
    Mendel
    @Mendel

    Jerry Giordano (Arizona Patrio… (View Comment):
    Lee, there is no evidence whatsoever that social distancing had any effect on the IHME projection

    Well, they say on their own website that social distancing had an effect on their projections:

    Does your model show the effect of social distancing and other measures?

    The data we have from several locations that have implemented social distancing suggest that they are effective.

    That sounds pretty clear to me.

    Jerry Giordano (Arizona Patrio… (View Comment):

    It may have, and I expect that it would have, but it is not proper reasoning to assume that the social distancing accounts for any changes.

    In fact, it is the opposite of scientific reasoning to make such an assertion. It is proper to make it as a hypothesis, and then to require actual evidence to demonstrate whether or not the hypothesis is true. Post hoc ergo propter hoc is not valid scientific reasoning.

    There actually is quite a bit of evidence that social distancing is having an effect. I don’t have time to go into all of it because it’s quite a bit more complicated than picking a date of when the measures theoretically went from 0% to 100% and then looking for a clear kink in the curve X days later. It’s also difficult to decipher from simple analyses because 1) in order to see any effect, there usually needs to be sustained community transmission – but many states in the US imposed lockdowns before it got that far (prematurely, in my opinion), and 2) when social distancing works well, it’s almost impossible to distinguish it from simply “a weak virus” without detailed analysis.

    But the evidence is strong enough not to be brushed away as unequivocally as you do, even though it’s also not strong enough to support the categorical statements of support most experts are voicing.

    Jerry, you continuously refer to the logic of scientific reasoning in a manner that is theoretically correct but not applicable in this situation. There simply isn’t enough data available to support either hypothesis – I could easily turn the tables and say that your suggestion that social distancing isn’t having any effect is equally unscientific. We don’t have enough case studies of regions without social distancing that are otherwise comparable enough and that record enough data.

     

    • #22
  23. Mendel Inactive
    Mendel
    @Mendel

    It seems to me that too many discussions about Covid-19 in the US are getting lost in endless circles: for one, the debate about whether the virus is really that dangerous at all, and for another, the debate about whether social distancing is actually working.

    Both questions are genuinely still up for debate. Unfortunately, there is enough compelling evidence and too little convincing evidence on either side to come to a conclusion quickly. Thus, we (and not just Ricochet members but the public at large) could easily waste weeks debating questions we simply can’t answer yet.

    That’s why I think a much better use of everyone’s mental capacity would be to leave the navel gazing about fatality rates and lockdowns aside and address the following questions:

    1) Is it possible that the virus has unique traits that make it worthy of respect regardless of how many people it actually kills (like its ability to infiltrate entire senior citizen homes before anyone realizes it)? Obviously yes. Instead of trying to categorize the virus as horrific or harmless, let’s just take the groups we know it’s very dangerous for and focus on their protection.

    2) Are there other forms of social distancing that are nearly as effective at stopping the spread of the virus while having much less of an impact on society? I think the answer here is an unequivocal YES!, but until people start taking the time to address this question we won’t make any progress on it.

    • #23
  24. Hammer, The Inactive
    Hammer, The
    @RyanM

    Mendel (View Comment):

    Hammer, The (View Comment):
    Their predictions always assumed an impact from social distancing. The fact that their number have been off by so much is not accounted for by social distancing. More likely, it suggests that the disease has been with us far longer than we supposed… which means it probably did its thing before we ever thought to do ours.

    This is actually the least probable explanation for why the actual numbers are coming in lower than the projections (even the ones including strict social distancing).

    From a scientific perspective, the notion that areas of the US (like WA state) with so few hospitalizations and deaths from Covid-19 have actually been silently infected strains credulity to the breaking point. Moderate-to-severe cases of Covid-19 have a distinct pathology that clearly presents to doctors as something unusual. So the notion that Covid-19 patients were going to the hospital but doctors were misdiagnosing them as having a common respiratory virus are highly unlikely. It is also unlikely that the virus managed to infect a large percentage of the population without sending anyone to the hospital given the throngs of patients seeking medical care in other regions affected by the virus. Furthermore, preliminary data from the hardest-hit town in Germany was released today suggesting that the number of undetected infections was “only” twice as large as the number of infections detected by PCR testing.

    I think the reasons why the actual figures are so much lower than the projections are much more likely to be one of the following: a) the reproduction number of the virus is lower than we think, b) it’s easier to prevent the spread of the disease than the models think, c) the hospitalization/mortality rates in China, Italy, and Spain will turn out to be much higher than in the US due to factors such as more elderly patients, more transmission within hospitals, worse healthcare systems, etc. Remember that most of the original data fed into the IHME algorithm was derived from those countries.

    I have been saying that it must necessarily be one or the other. If it is true that one asymptomatic person can infect roomsfull of people at once, and 80% of cases are asymptomatic (and both are commonly claimed), then it would be impossible for this to not be extremely widespread.  If that is not true, then neither of those claims are true. The problem, for me, is… Many of the “facts” about this virus that are most commonly cited actually contradict one another.

    • #24
  25. Hammer, The Inactive
    Hammer, The
    @RyanM

    D.A. Venters (View Comment):

    Jerry Giordano (Arizona Patrio… (View Comment):

    Hammer, The (View Comment):

    Lee (View Comment):

     

    I want to chime in and agree with The Hammer here.

    Lee, there is no evidence whatsoever that social distancing had any effect on the IHME projection, or that it has had any effect on the actual death rates or case rates. It may have, and I expect that it would have, but it is not proper reasoning to assume that the social distancing accounts for any changes.

    In fact, it is the opposite of scientific reasoning to make such an assertion. It is proper to make it as a hypothesis, and then to require actual evidence to demonstrate whether or not the hypothesis is true. Post hoc ergo propter hoc is not valid scientific reasoning.

    I have been carefully tracking the decline in the rate of increase of reported COVID-19 deaths in the US. I expected a lag of about 3 weeks before social distancing would have an effect on the death rate. That should have occurred somewhere around April 1, give or take a few days. There has been no noticeable change in the graph.

    It is also possible the projection simply underestimated how effective the social distancing rules and practices would be. I doubt there was much data out there to give them an idea of exactly what impact those changes would have. Thankfully, what we’ll never know what the numbers would have been without it. But if we know that the disease spreads by social contact, then there is no way that the social distancing could fail to have some impact.

    I say maintain the social distancing and stay-at-home orders until mass testing is available and practical, even for asymptomatic people, early detection and effective treatments are out there and available for patients. From the headlines, those things could be just a few weeks away. Even then, be prepared to lock down again if there is a spike until a vaccine comes along.

    Social distancing assumes one fact that doesn’t make sense. Namely, that asymptomatic people are highly contagious.  I can pretty easily tell if I’m feeling sick or not, but I’m told to stay 6 feet away from everyone regardless.  Either that is abject nonsense, or we would necessarily have to have thousands or millions of unwittingly infected… I’d accept the whole “stay home if you’re sick” version of social distancing, but the full lockdown assumes facts that contradict what is otherwise being claimed about the nature of this disease.

    • #25
  26. Hammer, The Inactive
    Hammer, The
    @RyanM

    Mendel (View Comment):

    It seems to me that too many discussions about Covid-19 in the US are getting lost in endless circles: for one, the debate about whether the virus is really that dangerous at all, and for another, the debate about whether social distancing is actually working.

    Both questions are genuinely still up for debate. Unfortunately, there is enough compelling evidence and too little convincing evidence on either side to come to a conclusion quickly. Thus, we (and not just Ricochet members but the public at large) could easily waste weeks debating questions we simply can’t answer yet.

    That’s why I think a much better use of everyone’s mental capacity would be to leave the navel gazing about fatality rates and lockdowns aside and address the following questions:

    1) Is it possible that the virus has unique traits that make it worthy of respect regardless of how many people it actually kills (like its ability to infiltrate entire senior citizen homes before anyone realizes it)? Obviously yes. Instead of trying to categorize the virus as horrific or harmless, let’s just take the groups we know it’s very dangerous for and focus on their protection.

    2) Are there other forms of social distancing that are nearly as effective at stopping the spread of the virus while having much less of an impact on society? I think the answer here is an unequivocal YES!, but until people start taking the time to address this question we won’t make any progress on it.

    @mendel – I am sincerely interested in your thoughts on the following questions.

    1) how deadly, actually, is this disease. That German-sounding Dr. In the video on pseud’s post made what I thought was a valid observation, that respiratory viruses have been with us for thousands of years, and there is no reason for this one to be fundamentally different (though drs are making progress re: how to treat it differently). Yet, media descriptions of it are like some horrific nightmare. 80% chance of mild cold, 20% chance instant death. Possible reinfection… 30 day incubation… Healthy nurses dropping like flies… Freezer trucks full of bodies… The list goes on.

    2) how contagious actually is it? Lockdown orders are essentially based on stories of one individual infecting thousands at a megaChurch, etc… Again, zombie-movie stuff. So we have to throw common sense out the window. No more focusing on stopping hospital and nursing home spread. Cancel little league, stay 6 feet from every living soul, crazy spaced out lines at grocery stores and bans on groups of all but the smallest nuclear families.

    See the problem I’m having, here? I’m ready to accept that some of these things could be true- but I can’t simultaneously believe in airborne transmission and not believe in the possibility of widespread antibody development, because at that point my brain starts to short out like Mudd’s Android…

    • #26
  27. Jerry Giordano (Arizona Patrio… Member
    Jerry Giordano (Arizona Patrio…
    @ArizonaPatriot

    Mendel, I appreciate your comments.

    I don’t think that I said that social distancing isn’t having an effect.  I said that I don’t think that there’s evidence that it is having an effect.  I think that under the scientific method, it is the proponent of a hypothesis — here, that social distancing has “flattened the curve” — that has the burden of proof.  I remain agnostic on the issue.

    I’m aware of the comment that you cited from the IHME site about social distancing, but they give no details.  If you read further on the page — or analyze their methodology, as I did previously — you’ll see that this appears to be an assumption of their model, not a conclusion.  They state:

    The model uses the time from implementation of social distancing measures to the peak of deaths in locations where this peak has already been reached or passed in order to model this relationship for locations where daily deaths have not yet reached their maximum.

    Initially, only Wuhan city had progressed far enough through its outbreak for this to be used in our model. An additional 7 locations have since reached or passed the peak of daily deaths (see updates April 5th) – many in less time than was observed for Wuhan city – and this broader evidence base is now used to forecast the date of the peak in daily deaths for each US state and countries in the EEA.

    I don’t think that they’re analyzing whether social distancing works.  We would have expected a peak of daily deaths to occur, with or without social distancing.  I don’t think that we know whether that peak occurred earlier because of social distancing.  In fact, if I understand the modeling correctly (the standard modeling, not the IHME model), social distancing would delay the peak, wouldn’t it?  If the idea is to “flatten the curve,” then the curve would be flatter but longer, so effective social distancing should cause the peak to occur later.  At least, this seems to be implied by the reasoning regarding social distancing.

    I agree with your point in comment #20 about the locality data not supporting the hypothesis that there was already widespread infection in most locations.  If the virus spread extremely rapidly in late February/early March, why are the fatalities so highly concentrated in so few areas, particularly New York and New Orleans?   

    Epidemiologist Knut Wittkowski hypothesizes that there are (at least) two strains of the virus, one of which is substantially more dangerous (his paper is here; he’s the guy in the video posted a couple of days ago here).  This might explain the strange pattern of the outbreak.  However, he hypothesizes that the virulent strain traveled from Hubei to S. Korea to Iran to Italy, and if so, S. Korea has unusually low fatality figures.

    I’m forming a new hypothesis — next comment.

     

     

    • #27
  28. Jerry Giordano (Arizona Patrio… Member
    Jerry Giordano (Arizona Patrio…
    @ArizonaPatriot

    We have a lot of evidence that COVID-19 is much more dangerous to the old, and notably more dangerous to men.  What it it’s particularly a problem for old men?

    I think that I’m going to develop this hypothesis.  The basic idea would be that the death rate in a country or region is heavily dependent on the proportion of old men.  About 2.75% of Italy’s population is males over 80, while the same proportion is only 0.95% in S. Korea.

    There could be an additional regional variation depending on how much contact old men have with the general population.

    • #28
  29. D.A. Venters Inactive
    D.A. Venters
    @DAVenters

    Hammer, The (View Comment):

    D.A. Venters (View Comment):

    Jerry Giordano (Arizona Patrio… (View Comment):

    Hammer, The (View Comment):

    Lee (View Comment):

    I have been carefully tracking the decline in the rate of increase of reported COVID-19 deaths in the US. I expected a lag of about 3 weeks before social distancing would have an effect on the death rate. That should have occurred somewhere around April 1, give or take a few days. There has been no noticeable change in the graph.

    It is also possible the projection simply underestimated how effective the social distancing rules and practices would be. I doubt there was much data out there to give them an idea of exactly what impact those changes would have. Thankfully, what we’ll never know what the numbers would have been without it. But if we know that the disease spreads by social contact, then there is no way that the social distancing could fail to have some impact.

    I say maintain the social distancing and stay-at-home orders until mass testing is available and practical, even for asymptomatic people, early detection and effective treatments are out there and available for patients. From the headlines, those things could be just a few weeks away. Even then, be prepared to lock down again if there is a spike until a vaccine comes along.

    Social distancing assumes one fact that doesn’t make sense. Namely, that asymptomatic people are highly contagious. I can pretty easily tell if I’m feeling sick or not, but I’m told to stay 6 feet away from everyone regardless. Either that is abject nonsense, or we would necessarily have to have thousands or millions of unwittingly infected… I’d accept the whole “stay home if you’re sick” version of social distancing, but the full lockdown assumes facts that contradict what is otherwise being claimed about the nature of this disease.

    I have no reason to doubt that asymptomatic people can be contagious, but I’m not sure social distancing is based solely on that assumption.  I think it is based, rather, on a few reasonable assumptions: 1) this virus is particularly dangerous, 2) -and this is practically a certainty rather than an assumption-the virus is spread from person to person by some level of social contact or proximity, 3) either people are contagious, to some degree, while asymptomatic, or people are, frankly, not good enough at diagnosing themselves when they have some kind of symptom (“it’s just allergies…I’m sure it’s just an ordinary cold,” etc.) and therefore aren’t cautious enough.  In ordinary times, huge numbers of people, understandably, still go out and work, or do what they have to do, when they know they are sick.  With a disease of this nature, that is a potential monumental disaster.  So…you get the 6ft guidelines and the stay-at-home orders.  

     

    • #29
  30. Jon1979 Inactive
    Jon1979
    @Jon1979

    Jerry Giordano (Arizona Patrio… (View Comment):

    We have a lot of evidence that COVID-19 is much more dangerous to the old, and notably more dangerous to men. What it it’s particularly a problem for old men?

    I think that I’m going to develop this hypothesis. The basic idea would be that the death rate in a country or region is heavily dependent on the proportion of old men. About 2.75% of Italy’s population is males over 80, while the same proportion is only 0.95% in S. Korea.

    There could be an additional regional variation depending on how much contact old men have with the general population.

    It was also noted that societies where touching in some way is more common seem to be the ones suffering more from the virus since its break-out from Wuhan. The more retrained/aloof a society is about contact being part of communal association, the less quickly the virus spreads. So old men living in a culture with a lot of hand shaking/kissing/hugging are in the highest-risk situation of anyone.

    • #30
Become a member to join the conversation. Or sign in if you're already a member.