Hospitalizations are not a static thing. This is what happens when public healthcare cannot cope with every patient and only the very sickest get a bed.

First published in December 2020.

There is something funny happening with US COVID hospitalizations. The proportion of COVID patients getting hospitalized is falling.

A lot.

Just recently.

My theory? As hospitals fill up, the bar for admission is rising. A patient who might have been admitted four weeks ago may get sent home now.

So, what do I mean by “The proportion of COVID patients hospitalized is falling”?

For months, you could reliably predict new hospitalizations. How? By taking cases seven days prior, multiplying by 3.5%. That is 3.5% (1 in 29) of those diagnosed today will be hospitalized about seven days later.

There is LOTS of caveats to this formula. Not all states report new hospitalizations (the formula takes that into account). One could build a 10-day lag formula (3.7% hospitalized by 10 days)

All data I report are 7-day moving averages from the COVID Tracking Project.

So, let’s look at the data.

  • On October 15, there are 53K new cases.
  • On October 22, you’d expect 1,844 hospitalizations (53K x 0.035).

What was it actually? 1,855. So far so good.

  • On November 1, there are 80K new cases.
  • On November 8, you’d expect 2,804 new hospitalizations (80K x 0.035)

What was it actually? 2,604. A little less. But fine.

  • On November 15, there are 146K new cases.
  • On November 22, you’d expect 5,111 new hospitalizations (146K x 0.035)

But there are only 3,670.

I’m ignoring data from last week because of the Thanksgiving messiness though this effect gets much more dramatic.

But here’s the fact: Over much of September and October, you could look at cases today and predict that 3.5% of that number gets hospitalized seven days later. But in November, that number starts falling.

  • Initially to 3.2% by November 8.
  • By November 15, it drops to 3.0%.
  • By November 22, it drops to 2.5%.
  • And by November 29, it is down to 2.1%.

So what’s going on? What does this mean?

May be more testing means we are picking up more cases? No. The percentage of test positivivity is rising from 5.1% (October 1) to 12.1% (November 15). So, the number of cases being missed is climbing.

The proportion of patients being admitted in hospital from identified cases should be RISING.

That 3.5%? It should go up. Instead, it is falling.

So what’s happening?

What you would expect – Doctors’ threshold for admission is likely going up.

In early October, with plenty of beds, a COVID patient who is clinically borderline likely gets admitted to ensure they do OK. By November 15, beds are in short supply, that person likely just goes home.

Of course, critically ill patients always get admitted. But over time, marginal admissions start disappearing. And as hospitals get fuller, what is defined as “marginal” keeps changing. Until you only admit the sickest folks.

And that’s what appears to be happening.

Here is the bottom line: 1 in 3 people who would have been admitted on October 1 aren’t being admitted by November 22. That’s a big change! And given the big rise in test positivity – it is likely much higher.

Best guess? We are admitting half the COVID patients we would have admitted on October 1.

Is this a problem? If those people don’t need hospitalization, is this bad? Well, on October 1, we would have said that they need hospitalization. So “need” is fluid.

But here is the other key issue. The evidence suggests that many of these patients now being sent home will likely do worse at home. Some may be OK – but others will come back sicker or even die at home.

One more thing. When hospitals fill up, the threshold for admission for everything goes up. Everything – COVID and non-COVID – is affected. So, borderline admission for heart failure? The person now goes home. A patient with an infected leg where you’d prefer IV antibiotics in hospital? They go home with oral antibiotics.

This is what is happening in hospitals across America right now.

This is not doctors being cruel. It is that with fewer and fewer beds available, the bar for hospitalizing anyone is rising. And it likely means that more people are suffering, getting worse, or even dying at home. All because our hospitals are really full.

So, what is the bottom line?

We can see in the data that we are likely admitting far fewer COVID patients than we would have just two months ago. This is likely due to very full hospitals. Because political leaders have politicized mask wearing and social distancing. It is a travesty.

So, remember: Hospitalizations are not a static thing. When hospitals get full, by definition you can’t hospitalize all the folks you would like to hospitalize. And many who would benefit from hospitalization suffer because only the very sickest get a bed. Everyone else goes home.🔷

Dr Ashish K. Jha, Physician, health policy researcher. Dean of the School of Public Health, Professor of Health Services, Policy and Practice, Brown University, Rhode Island.

[This piece was first published as a Twitter thread and turned into the above article on 1 December 2020 with the purpose of reaching a larger audience. It has been minorly edited and corrected, and published with the author’s consent. | The author of the tweets writes in a personal capacity.]

(Cover: Screenshot of a Texas hospital overwhelmed by coronavirus patients | CBS Evening News.)