Friday, April 3, 2020

There are 3 windows into pandemic deaths. Two are absolutely horrifying. And I’m reluctant to even tell you about the third.


  
Yesterday’s numbers (from Worldometers, as of about 8 PM EDT April 2)
Total US confirmed cases: 245,442
Increase in cases since previous day: 30,085 (vs. 26,710 increase yesterday)
Percent increase in cases since yesterday: 14% (vs. 14% yesterday)
Percent increase in cases since 3 days previous: 30% (vs. 31% yesterday)

Total US deaths as of yesterday: 6,098
Increase in deaths since previous day: 98 (vs. 1,054 yesterday)
Percent increase in deaths since previous day: 19% (vs. 26% yesterday)
“Set in stone” US deaths* over course of pandemic:  118,755 (based on 4% case mortality rate)
*This number assumes a) Total cases grow by 30% into the future (= yesterday’s 3-day growth rate in cases); b) We impose a massive lockdown, with prohibition of all non-essential travel, today; c) New cases drop to zero in 28 days, because of the lockdown; d) testing is widely available by the 28-day mark; and e) case mortality rate = 4%. To consider a 6% mortality rate, multiply each projection by 1.5. For 8%, double it. For comparison, Italy’s case mortality rate is currently 11.75%.

Projected as of April 10 (7 days from today):
Total expected* cases: 473,139
Total expected* deaths set in stone** over course of pandemic: 228,733
Projected** number of actual deaths on 4/10 alone: 3,885
* The expected cases and deaths set in stone numbers assume a) Total cases grow by 30% into the future (= yesterday’s 3-day growth rate in cases); b) We impose a massive lockdown, with prohibition of all non-essential travel, on April 10; c) New cases drop to zero in 28 days, because of the lockdown; d) Testing is widely available by the 28-day mark; and e) case mortality rate = 4%. To consider a 6% mortality rate, multiply each projection by 1.5. For 8%, double it. For comparison, Italy’s case mortality rate is currently 11.75%.
** Projected deaths = previous day’s new deaths number, grown by that day’s 3-day percentage growth rate. Note this is calculated completely differently from the deaths set in stone, which refers to projected deaths over the entire pandemic, and is calculated by multiplying expected cases by the mortality rate.

Projected as of April 17 (14 days from today):
Total expected* cases: 911,309
Total deaths set in stone** over course of pandemic: 554,406
Projected*** number of actual deaths on 4/17 alone: 25,701 This is down 9,000 from the number yesterday, because the 3-day growth rate dropped from yesterday to today. Hopefully, it will continue to drop, but that depends on how serious the Federal government is about enforcing social distancing. Currently, they leave a lot to be desired in this regard.
* The expected cases and deaths set in stone numbers assume a) Total cases grow by 30% into the future (= yesterday’s 3-day growth rate in cases); b) We impose a massive lockdown, with prohibition of all non-essential travel, on April 17; c) New cases drop to zero in 28 days, because of the lockdown; d) Testing is widely available by the 28-day mark; and e) case mortality rate = 4%. To consider a 6% mortality rate, multiply each projection by 1.5. For 8%, double it. For comparison, Italy’s case mortality rate is currently 11.75%.
** Projected deaths = previous day’s new deaths number, grown by that day’s 3-day percentage growth rate. Note this is calculated completely differently from the deaths set in stone, which refers to projected deaths over the entire pandemic, and is calculated by multiplying expected cases by the mortality rate

Reported case mortality rate so far in the pandemic in the US:
Total Recoveries in US as of yesterday (4/2): 10,411
Total Deaths as of yesterday: 6,098
Deaths so far as percentage of closed cases (=deaths + recoveries): 37% Let’s be clear. This means that, of all the coronavirus cases that have been closed so far in the US, 37% of them have resulted in death. Compare that to the 4% mortality rate I’ve been using to calculate total pandemic deaths, based on cases. Of course, this number will come down as time goes on and more cases are closed in which the victim recovered. But it’s only come down by about 4 percentage points since Worldometers started publishing the recovery rate on March 26, and on about half the days, it’s gone up. I’d say it’s much more likely my 4% mortality rate will turn out to be too low, after the pandemic’s over and all of the bodies have been counted, than it will be too high.

Date on which 200,000 deaths will be set in stone: April 9
Date on which 500,000 deaths will be set in stone: April 19
Date on which 1 million deaths will be set in stone: April 28

I’ve come to realize that this blog is about death. Most, if not all, of the news stories and opinion pieces I’ve read on the pandemic talk mainly about cases in their projections. When they talk about deaths, they quote the official sources, who tend to look completely on the optimistic side of things. For example, the White House press conference on Tuesday gave a range of 100,000 to 240,000 for total deaths, which will be out of reach within two weeks (the lower end is already out of reach).

And these estimates are based on implicit assumptions that are almost exactly like mine: a) there will be a massive nationwide lockdown by next week, including prohibition of all non-essential travel; b) it will be 100% successful, and new cases will drop to zero 28 days later; and c) testing will be freely available 28 days later, since the virus will come roaring back if that’s not the case. These are the same assumptions I use when I compute my “set in stone” estimates for total pandemic deaths. Unfortunately, I see no movement at all to enforce a total lockdown and travel ban on the Federal level, and it’s very doubtful even now that testing will be available in 28 days, in the numbers necessary to restart the economy (I would think many businesses will want employees to be tested every day, before they’ll let them in the workplace. The same with all medical workers, grocery store workers, etc. We could easily need more tests every day than we have available at all, even a month from now).

More importantly, my set in stone estimates of total pandemic deaths are based simply on the reported case numbers, grown by the most recent 3-day growth rate. Yet there’s widespread agreement among epidemiologists that the actual number of cases in the US today is at least ten times the reported number (and the Prime Minister of Australia said the same thing yesterday about his country, although their reported cases are still far below ours). So what the total cases number reflects now isn’t total cases at all: it’s simply the availability of tests. As tests become more and more available, total cases will grow faster and faster, and my set in stone numbers will grow even faster than they are.

My set in stone estimates are also based on the estimated case mortality rate; I’m using 4% for that now, but there are lots of reasons to think that’s too low. More on this below. So as of this moment, my set in stone numbers can’t be trusted as a long-term estimate of total deaths. This is the first of the three “windows” mentioned in the title.

What can be trusted? The second window is most reflective of actual cases, and that is total reported deaths. The virus can kill anybody, regardless of whether there case has been reported or not. So the daily deaths numbers are in fact a reflection of actual cases, not reported ones.

Up until this week, I didn’t try to project this number, since there were so few data points and initially the numbers were so low. However, we now have a month of data points, and the numbers are high enough that they won’t jump around as much. What do these numbers show? In contrast to the reported case numbers, which were growing at around a 100% three-day rate a few weeks ago but are now growing at about 30% and hopefully will continue to fall (because of social distancing, of course), the daily new death numbers don’t seem to have a long-term trend, and are in general growing around 100% every three days (yesterday it was 92%).

And will the growth rate in new deaths decline in the near term? There’s no particular reason to believe that; indeed it would probably be expected to go up, since there are so many more uncounted than counted cases out there. As time goes on, there will be many more previously uncounted cases dying than counted ones (remember, an uncounted case usually doesn’t get counted until the victim feels bad and goes to the hospital).

I’m projecting these numbers out at the current three-day growth rate. You can see some of these projections above:

  1. One-day deaths on April 10 will be 3,885. This will be the second day on which total COVID-19 deaths will exceed deaths on September 11.
  2. One-day deaths on April 17 will be 25,701. This is down by about 9,000 from the number I reported yesterday for April 16, because the growth rate fell from 105% to 92%. Even then, of course, this is more than eight times the September 11 toll.
I’ll give you a couple more numbers that are further out, although of course the accuracy gets less and less as you go out. On April 24, there will be 163,253 new deaths recorded. And on May 3, total one day deaths are over one million.

So this is the second window. What about the third? I’ll discuss that soon. I need to go back to my day job now, plus I want to give you time to absorb the numbers I just put down, especially the idea that in May we’ll start to have deaths in the millions every day.

I’ll leave you with one thought: The only way to prevent death numbers like this is massive and total social distancing and a total halt to non-essential transportation. At first, Italy, Spain and the UK all tried halfway measures like the ones we have in place now, and they realized they weren’t going to work. And Sweden, which just a week ago was touted by the New York Times as a country that had seemed to find a way to control the virus without going the total lockdown route, acknowledged they’d made a mistake and instituted a total lockdown a few days ago.

What’s the difference between those countries and us? They have governments that can look at the evidence, admit they made a mistake, and change course. Because of this, when the pandemic’s over, our total deaths will make theirs pale by comparison (both in absolute terms and as a percentage of the population), even if we instituted a total lockdown today.



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