1/n Not long after I did the attached chart of cases by age, I realized I could use the Ontario database to predict how deadly each day's set of new cases might be, based on the age breakdown and their average death rates.
2/n First, we know two important things about the COVID-19 death rate.
1. It's become a lot lower over time, probably because we're better prepared to treat it.
2. It takes some time for some patients to die.
3/n If you're looking to estimate how likely any given patient is to die, it's simple enough to resolve those issues.
1. Throw out data from the spring.
2. Throw out recently infected cases, and any case listed "not resolved".
4/n Another important thing to note is that some folks are especially vulnerable to COVID-19, people in nursing homes, especially.
Thankfully, the Ontario database tells you if someone caught the virus in an outbreak — and that's a pretty good proxy for those nursing home cases.
5/n So: We have a method.
Take the age distribution and outbreak status of each day's cases, and run that against the average chance of death for similar cases reported June thru end-Sept.
For Ontario, that looks like this:
6/n Clearly, 1. age is the primary factor in whether any given patient dies, and 2. Ontario's was much better at treating the average patient over the summer than in the spring.
OK. Now it's just a matter of taking each day's set of cases, and using these averages.
7/n And here you have it, Ontario's COVID-19 pandemic by a single metric of "expected deaths."
Basically, based on the age and outbreak status of the folks who got sick in Ontario today, this is the number you'd expect to die, based on the rates we saw over the summer.
8/n The *other* thing you achieve by normalizing to the averages over the summer is you now have the ability to directly compare wave 1 with wave 2.
(Add this to my endless list of tweets on why deaths aren't yet spiking in Ontario's fall wave).
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The labs first need to *have* samples to be able to test them, so the fact more tests were collected than tested yesterday does not yet suggest there's a "backlog" problem.
With big input numbers, it's normal for a large total of tests to be in the queue at the end of the day.
The question is whether the labs can handle this input after it comes in, so should watch to see if the completed number gets back up into the mid-to-high 40k range tomorrow.
As of 8 pm Wed., Ontario's regional public health units are reporting another 373 confirmed or probable COVID-19 cases, with 4 more deaths.
The 7-day avg. is 🔺 to 403 cases/day and 🔺 to 1.7 deaths/day.
First time the 7-day avg. has been north of 400 cases/day since May 26.
Accounting notes:
- Toronto reported 129 new cases but the unit's total rose by 99. In the past, this would suggest data cleaning scrubbed 30 cases, but I don't know yet if that's the case today. Regardless, my total for the day includes 129 from Toronto.
- The province's total for Toronto from the same reporting period was 102.
- The province also had 0 in Middlesex-London, but the unit reported 12.
- So: Add 30ish from Toronto and 12 from London to province's 335 from this morning, and it's much closer to what I'm seeing.
As of 5 pm Tues., Ontario's regional public health units are reporting 50,055 confirmed or probable COVID-19 cases, with 2,872 deaths.
The 7-day avg. is 🔺 to 393 cases/day and slightly 🔽 to 1.4 deaths/day.
470 cases today by my count.
7-day avg. is doubling every 9-10 days.
After a while, you kinda run out of ways to say "this looks bad," but it really is on pace to get awful.
No matter how many more cases we're finding now vs. the spring, Ontario can't sustain this pace of infection for long — and if it does, these rates get ugly quick.
... and then hospitalizations and deaths will follow.
Meantime: Compare where Ontario's larger health units are at now (left) vs. the start of August (right):
From falling cases to frightening growth rates.
It's a hell of a turnaround in less than two months.