When I ran a projection at 25% yesterday, it showed us at 118,750 for this morning. Right now the tracker shows 115,235. I wouldn’t make too much of that difference. Yes, every bit lower today is magnified over time, so it really is good to miss the projections on the low end. On the other hand, these projections are meant mostly to give a general idea of where we are headed, not a precise count.
Yesterday looks to have been a good day, with only about 22% growth. However, it’s too early to say whether that is the beginning of a trend or just a good day. Also, the numbers sometimes get revised even a day or two later. It’s tough to track these many tests and cases without an established infrastructure for doing so. Revisions are meant to produce a more accurate count even if it’s delayed.
Today, I’m going to start at 115,000 and continue with a 25% growth rate for the projection. I’m going to limit the projection to 10 days.
3/28 115,000
3/30 179,688
4/1 280,762
4/3 438,690
4/5 685,453
Again, I really don’t know if we’ll have the testing capacity to identify that many cases. I’ll try to find some data on what our capacity is and how it’s growing.
We’re also going to start seeing increasingly alarming numbers of deaths. I’ve decided to go ahead and project those also. In this case, I’m not going to base the projection on the growth rate of reported deaths. Rather I’m simply going to apply the fatality rate to the case projection. Basically, I’m assuming that the growth rate of death will be the same as that of cases. I may change that methodology later. If I do, I’ll let you know.
The attached chart shows the fatality rate over time. Because this is the Case Fatality Rate (CFR), it just reports the percentage of known cases resulting in death. In the early days, we mostly only knew about the most severe cases, so the CFR was higher. As we have been able to identify more cases, the CFR has has dropped a lot. Of late it’s been hovering right around 1.5%. That’s the number I’m going to use for the projection.
3/28 1,725
3/30 2,695
4/1 4,211
4/3 6,580
4/5 10,282
Right now, I only see 1,715 reported deaths, so we’re starting in a bit better shape that the projection. The worry will be that as hospitals get overwhelmed, the CFR will get substantially larger. This has been the problem in Italy. The CFR in Italy is in the neighborhood of 10%. This effect will vary quite a bit by region, which is another reason I expect numbers to get wobbly.
Stay safe, stay healthy, stay at home as much as you can and take appropriate safeguards when you can’t stay at home.