A chart that’s been making the rounds on twitter claims that, while many students have been tested positive, NO students have been hospitalized. I’ve seen this cited many, many times. Patent zero appears to be an assistant professor at Brown University.

I don’t know why someone who would appear to have a good background for epidemiology would post this, but it’s pretty deceptive.

His heading is absolutely correct; there have been zero hospitalizations reported by these institutions. But the reason is important. Let’s look at some of his sources.

…and on and on. The table is correct – none have been reported but it’s because the schools are not reporting this statistic. It’s therefore silly at best (deceptive at worst) to even include the column. The table says that schools aren’t reporting hospitalizations and deaths, not that they haven’t happened.

If you want a better way to measure this, let’s go to the Washington state dashboard which does report all outcomes by age. https://www.doh.wa.gov/Emergencies/COVID19/DataDashboard

In Washington, there have been 83,000 cases, 7200 hospitalizations, and 2000 deaths. of those, kids aged 00-19 make up 14% of cases, 2% of hospitalizations, and 0% of deaths.

Distributing these, we get to the following statements:

  • if your 19 year old tests positive for covid, they have a 1.2% chance of being hospitalized
  • if your 19 year old test positive for covid, they have a 0.05% chance of dying.

Among the table above, that would imply among the 25,000 positive tests, 310 kids went to the hospital, and 13 died.

UPDATE: A commenter raised the point that hospitalization rates have been falling since the beginning of the pandemic. This is a good point, although one question is whether the falling rates are due to changing age distributions (more younger would mean less hospitalizations). Looking at the King County data, it turns out that even within an age band, hospitalizations have falling. To account for this, I divided the data into two period: pre July and july until today.

The 0-19 age band is definitely being hospitalized less than they were. If your 19 year old gets sick, their p(hospitalization) before July was 2.14%. Since July, that rate has fallen to 0.56%. Both stats are based on over 1000 cases, so are probably reliable. Since July, there have been NO deaths of kids under 20 in King county, so the p(death) is clearly VERY low in this age range.

This new range would mean that out of 25,000 cases, we’d project about 140 hospitalizations at the schools in the table.