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Nearly half for other reasons? How misleading are Covid hospitalization numbers?

New research gives a shocking answer to a question people have been asking for well over a year: what does the statistics on “Covid-19 hospitalization” even mean?

As I wrote about hospitalizations nearly a year ago in our “Fog of Covid-19 Data” series,

In regular conversation, a hospitalized COVID-19 patient would mean someone whose COVID infection is so bad it’s put him in the hospital.

To Gov. Roy Cooper’s Department of Health and Human Services, however, it means someone who is in the hospital for any reason and who has tested positive for COVID-19. That’s a key distinction. I’ll explain.

DHHS admits no distinction between a hospitalization for COVID and hospitalization with COVID. Hospitalizations for COVID are the dangerous infections people rightly worry about. Hospitalizations with COVID are when people are in the hospital for other reasons — a chest ailment, a car accident, a medical procedure, etc. — and as part of the routine clinical assessment, they test positive for COVID.

How many people are in one group and not the next? It’s hard to tell from this vantage point. Counting the two groups together, however, only inflates the number and gives the impression that dangerous infections are higher than they are. How much higher, who can tell?

While government agencies, federal and state, have been very coy about disaggregating this population for obvious reasons (if people knew that the actual number of people put in the hospital by Covid-19 was much lower, it would mean less cause for panic and executive orders), we recently got a glimpse of how big it could be for one particular population: the already vaccinated.

On July 26 the Centers for Disease Control and Prevention released a report on post-vaccination (“breakthrough”) Covid-19 hospitalizations and deaths. The reason for this rare bit of transparency is also political: if people knew that the actual number of vaccinated people put in the hospital by Covid-19 was much lower, it would mean less cause for concern … about vaccinations.

The revelation was that roughly one-fourth of “breakthrough” Covid-19 hospitalizations (26%) and deaths (24%) were “asymptomatic or not related to Covid-19.”

In discussing that report, I wrote:

This revelation leaves several questions, however. Do “breakthrough” hospitalizations and deaths behave differently from other Covid-19 infections? Would that mean more inflation in “breakthrough” cases — or less?

This new research gives an indication of the answer, and in so doing, the researchers call for better metrics.

VA research: Nearly half of “Covid hospitalizations” were of people in the hospital for other reasons and subsequently testing positive

In a preprint by Nathan Fillmore et al. looking at VA hospitalizations, the researchers found the following:

Vaccination availability is expected to de-couple SARS-CoV-2 case rates from hospitalization rates, because vaccinated patients develop less severe disease and unvaccinated patients tend to be younger and healthier. Thus, metrics designed to determine the level of risk in a community, and in turn to inform decisions about restrictions and mitigation strategies, should increasingly focus on hospitalizations rather than cases. However, after vaccines became available in late 2020, routine inpatient screening, common or mandated in many facilities, may identify incidental cases. If hospitalizations are used as a metric for policy decision-making, patients hospitalized for the management of COVID-19 disease should be distinguished from patients who are hospitalized and incidentally found to be infected with SARS-CoV-2.

That is the distinction we are lacking: “hospitalized for the management of Covid-19 disease” (i.e., Covid put them in the hospital) vs. “hospitalized and incidentally found to be infected with SARS-CoV-2” (i.e., in the hospital for some other reason and testing positive for Covid as part of admission).


The proportion of inpatients with any documented SpO2 < 94% or oxygen supplementation changed over time (P < 0.001, Figure). From 3/1/2020-1/20/2021, the proportion of hospitalized patients with moderate-to-severe disease was 64.0% (95% CI, 63.1–64.9%) and from 1/21/2021-6/30/2021, was 52.0% (95% CI, 50.9–53.2%).

In other words, barely over half (52%) of Covid patients in the VA during the post-vaccination period were hospitalized for the management of Covid-19 disease. The rest (48%) were in the hospital for some other reason and incidentally found to be infected with SARS-CoV-2.

Driving the point home:

With widespread vaccination, the current definition of COVID-19 hospitalizations includes progressively more mild or incidental diagnoses, for example, cases identified prior to surgery or prior to discharge, rather than hospitalizations due to severe COVID-19. Other recent studies similarly found that current definitions of “COVID-19 hospitalizations” combined with routine, and often mandatory, screening testing of all admissions may substantially overestimate the number of hospitalizations caused by SARS-CoV-2 infection.

Take note of those: cases “identified prior to surgery or prior to discharge, rather than hospitalizations due to severe Covid-19,” and definitions that conflated “Covid-19 hospitalizations” with cases detected from “routine, and often mandatory, screening testing of all admissions.” Continuing:

In a pediatric population, 41% of reported admissions associated with SARS-CoV-2 infection were for reasons other than COVID-19, rates similar to those found when the simple definition of moderate to severe disease was applied in our cohort.

The problem extends to children’s hospitalizations, opacity about which is especially being used to inflame passions for emergency orders for mandatory masking and vaccination for schoolchildren.

The authors conclude again for a plea for better data: “Consideration should be given to updating definition of COVID-19 hospitalizations to improve differentiation between hospitalization caused by COVID-19 and those associated with detection of SARS-CoV-2 through the addition of straightforward and objective measures of disease severity.”

Jon Sanders / Research Editor and Senior Fellow, Regulatory Studies

Jon Sanders studies regulatory policy, a veritable kudzu of invasive government and unintended consequences. As director of regulatory studies at the John Locke Foundation, Jo...