Thread by @TomBossert

The theme here is wrongheaded. The guy quoted is looking at hospitalizations “every day.” That’s not enough. Lag and delay are hard concepts for people to understand, but future planning in this case is about mathematical forecasting (not modeling). We must look beyond our noses.

https://twitter.com/brithume/status/1319994529668366337

Every time we see a spike in new cases, it is followed by an increase in hospitalizations and deaths. But, there is a time delay between the two for several reasons.

At the individual level, a person takes time to get sick and die. At a macro level, the amount of virus in a given community and the type of people exposed can vary. Sometimes we see outbreak cohorts of young, healthy people without a lot of lagging hospitalizations and deaths.

But, probability is the key here. The more virus in the population, the greater the odds it spills over into every age group and demographic. Those odds translate into predictable, albeit delayed, increased hospitalizations and deaths.

As predicted several weeks ago (and in some sense months ago) hospitalizations are now up.

https://twitter.com/scottgottliebmd/status/1320138140116525056

Probability is the key. The math is not linear, so it’s not intuitive. But, once you get how it works, this becomes clearer. In some counties today, if you had a gathering of 25 randomly selected people, there would be a 90% chance—or better—of one of them being infected.

In other counties, like the one my parents live in, the 25 person gathering would stand an 11% chance of including an infected person. Invite 50 people, and the chance becomes 21%.

Given the new case totals in the United States, if you have a gathering of 1,000 people or more, the odds are almost 100% that at least one person in attendance is infectious. Go to covid19risk.biosci.gatech.edu and see what your odds are based on different size events.

So, making concerted efforts now, to include locally targeted and temporally limited interventions and closures—not national shutdowns—will allow us to reduce the odds that our loved ones can gather safely on Thanksgiving day.

If we wait until the new hospitalization numbers are up on the day before Thanksgiving, there won’t be sufficient time to improve your odds. Let’s adopt a National approach with locally appropriate interventions. Now.