Post #1279: COVID-19 trend to 10/5/2021: No change

Posted on October 6, 2021

 

The U.S. new case rates continue to fall.  Alaska appears to be well and truly over its hospital capacity crisis.

As of today, U.S. new COVID-19 cases / 100K / day stands at 31.5, down 39 percent  from the 9/1/2021 Delta peak, and down 12% over the past seven days.

Data source for this and other graphs of new case counts:  Calculated from The New York Times. (2021). Coronavirus (Covid-19) Data in the United States. Retrieved 10/6/2021, from https://github.com/nytimes/covid-19-data.”  The NY Times U.S. tracking page may be found at https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html.


The Alaska Conundrum

Below, Alaska appears to be well and truly over its hospital bed crisis at this point.  That’s what I infer from the US CDC counts of newly hospitalized COVID-19 patients, versus the current stock of all COVID-19 patients who are in the hospital.  You can think of the latter as the total beds devoted to COVID-19 patients. 

Source:  CDC COVID data tracker.

The core of their hospital crisis lasted two weeks.  That’s the difference between the peak of the new admissions curve (9/12/2021), and the peak of the occupied beds curve (9/27/2021).  For two weeks, they appear to have been rationing new hospital admissions in the face of rising new cases.  But now, the fall in total beds occupied by COVID-19 cases shows that there is capacity for new admissions currently.

This analysis does not account for the possibility that ICU beds and/or ventilators are still being rationed, even if hospital beds are not.  But we can reasonably infer that the worst of it — where there literally wasn’t even an inpatient bed available — is over for now.

Here’s the odd thing that I’ve seen happen time and again.  They were saved by a decline in new cases.  It’s not as if they were able to find new beds.  The Federal government didn’t come to the rescue.  Instead, once again, the pandemic ran right up to the point where the crap was hitting the fan.  But not much further.

As has happened in so many states, new COVID-19 cases rose right to the point where hospitals were full.  And then backed off. 

Perhaps I find this striking only because I spent the early part of my career studying U.S. hospitals.  But to me, this is a huge conundrum, and it may not be obvious to anybody else.  But here goes:

There is no natural relationship between the spread of disease and hospital capacity in a state. 

Hospital capacity is part economics, part regulation, part historical accident.  It was predetermined by all of those factors well in advance of the pandemic.

And yet, within some small margin of error, the pandemic appears to respect that hospital capacity boundary time and again.  Last year, I attributed that to the fact that Republican governors did not have the political latitude to take action until the hospitals were full (e.g., Post #890, The Republican Playbook).  But this year, we’ve seen the same phenomenon across several states, when nobody did anything to reduce spread of disease (Post #1220).  Republican governors failed to take action, period.

You might guess that maybe the causation here is due to behavior.  Maybe residents of a state would get serious about COVID-19 hygiene measures when they start hearing stories about the hospitals being full.  And that’s the causal link between hospital capacity — which is largely the result of historical accident — and peak rate of new cases in the pandemic.

But you’d guess wrong.  At least for Alaska.  Apparently, stories of people dying because hospitals were full did not phase Alaska residents in the least.  Or, to be clear, didn’t motivate them to bother to wear masks.

Source:  Carnegie-Mellon University Covidcast.

 

 

Nor did those well-publicized deaths motivate Alaskans to get vaccinated, to any material degree.

Source:  CDC COVID data tracker.

To me, that’s a real puzzler.  We’ve seen this time and again.  New COVID-19 cases run right up to the hospital capacity boundary.  But they never hugely overrun that.  We can’t attribute that to actions by respective state Governors, because, of late, there haven’t been any.  It’s even a stretch to attribute that to more caution on the part of those states’ residents, because, as we see with Alaska, that just didn’t happen.

As of today, I have nothing that even remotely begins to explain this.  This has happened too many times to be mere coincidence.

My newest best guess — after so many wrong ones — is that we’ve seen it happen so often because the concept of hospital system capacity is vague.  In other words, we hear about this as hospitals begin to get stressed.  But they can then change behavior in various ways.  They can cancel elective admissions, staff unused beds, open temporary ICU space, informally raise criteria for acute hospital admissions, ship patients out-of-state, triage patients in ER space and from the back into ambulance space, and so on.

Up to now, I’ve been thinking of hospital system capacity as some firmly drawn line.  And that’s just not so.  And as a result, whenever a state gets some fairly high rate of daily new COVID-19 cases, they end up with a stressed hospital system.  Their hospital system is nearly “at capacity”.  But in most cases, not really.  Only in Alaska and Idaho do they appear to have hit a firm upper limit on the number of new COVID-19 cases that clearly required an inpatient level of care, and that the hospital system could accommodate.  Only in Alaska, so far, does it both appear that patients were denied needed beds, and reporting confirms that patients died for lack of beds.  (E.g., this one, but there are many similar stories).

The upshot is that maybe we hear about hospitals reaching capacity over a very broad range of high levels of new COVID-19 case rates.  With that view, “hospitals are stressed” is just another way of saying “new case rates are high”.  Which is something that is, by definition, going to occur on or around the peak of any significant wave of COVID-19.

But if you take that to its ultimate conclusion, you should find that unsettling.  At least, I do.

I had been thinking that there most be some mechanism that somehow limits the extent of the pandemic.  Some feedback that eventually puts a lid on new COVID-19 cases, and so protects us from the possibility that COVID-19 could vastly overrun state hospital capacity, resulting in mass deaths.

By contrast, absent any real feedback mechanism that caps the rate of new COVID-19 cases, I have to wonder if, at some point, there’s going to be a major violation of the COVID-respects-hospital-capacity “rule”.  Which brings me to my next topic.


Winter wave, and predictions as good science.

There’s still no obvious sign of the start of a winter wave. No upturn in the red line below, which now ends on 10/5/2021.

And yet, I still haven’t changed my mind about the likelihood of a U.S. winter wave.  And it’s not that I’m stubborn.  My favorite quote attributed to an economist goes something like “When the facts change, I change my mind.  What do you do?”

I’ve made my prediction, I’ve made that public.  And if the facts change, I’ll change my mind, publicly.  That’s just good science.

But I’ve already highlighted my reasoning in the very first chart, above.  The U.S. Midwest and Mountain regions are now emerging out of the pack, and now have the highest average rates of new COVID-19 cases in the country.  Those were the regions that led the 2020 winter wave.  Meanwhile, the U.S. case average is falling because new cases rates are down 80% in the U.S. south.

If I look back to the 2020 winter wave, the Midwest and Mountain areas didn’t really see a big uptick in cases until the second half of October.  So, as of now, the 2021 Winter wave isn’t even late.  Yet.  Despite the clear continued improvement in the U.S. average, I’m not declaring my prior prediction to be wrong.  I think we need to wait a bit and see.