I’ve been posting the above data pretty much each day because it tells a pretty solid story of what is happening in the US. Trends toward lower case rates and death rates continue from about a week ago when these trends started to become noticeable. Now even New Jersey is showing a slowdown in their death rate (note that their acceleration over the last 3 days is negative right now). Many of the non-NY area states are showing death rates that are essentially linear. Hoping this is a long-term trend and not just a temporary one.
Recovery Data
A while back I showed what a Cumulative Flow diagram looked like in the manufacturing world. This diagram can also be generated using Confirmed Case data and Recovery data. For a while JHU dropped their recovery data when (I think) they figured out that some countries were gaming that data to make their societies look better (Iran, China, Vietnam…). But since Europe is entering into the recovery portion of their initial outbreak, I thought I’d show a couple of European countries that are doing well (and whose data is trustworthy).
Switzerland has been a curious case for a while as it is sandwiched in between countries with high death rates but managed to keep its own death rates down. Here we see the raw numbers for their confirmed cases, recoveries, and deaths in one diagram. Things to note:
- When looked on the same scale as cases, deaths are very small. Keep this in mind should you be tempted to panic. The vast, vast majority of cases do NOT end in death.
- The horizontal distance between the orange confirmed cases line and the green recoveries line at any point is the cycle time for the outbreak. So go on the y-axis to the 5000 case mark and go over to the right on the diagram until you hit the orange line. You can see that the 5000th case happened on 3/20/2020. Now continue on the same horizontal line to the green line. The 5000th recovery happened on 4/3/2020. This shows that the cycle time to “clear” 5000 cases is 14 days. You may remember that early on we were seeing (from China and Singapore data) a cycle time of about 22 days. I wonder if we’re seeing better cycle times in Switzerland due to advanced medical care?
- The vertical distance between the lines is the number of active cases at any point. So do the same exercise that you did in #2 except this time go to 4/3/2020 on the x-axis. Trace up to the orange line. On that day you can see there had been 20K confirmed cases in Switzerland. Now go back down to the green line. There were 5K Recoveries that had occurred by 4/3. That means there were 15K active COVID-19 cases in Switzerland on 4/3. In the manufacturing world, we call that the “Work in Progress” or WIP. This is an indicator of how much work — in this case, COVID-19 active cases — in the pipeline.
- I suspect we will see the cycle time shrink a bit over the duration of this outbreak as hospitals become more productive. I also expect that we’ll see the active cases at any time shrink down too, because the virus will run out of easy targets. Both of these are good things to watch for, because they’ll indicate that we humans have asserted a bit more control over the situation.
- Note that the slope of the confirmed case line is decreasing. This is happening across Europe. Maybe this is a sign that the worst portion of their outbreak is behind them.
Here’s one more CFD. This time for Germany. Note the same trends.
