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Friday, May 15, 2020

The Rate of Covid-19 Spread in the U.S.: Optimism in Reading and Interpreting Graphs

Since death is involved, COVID-19 is a serious matter. Dismissal of what's happening should be dismissed.

Yet there is too much disinformation and distortion about the virus. It may not be intentionally deceptive. It may be ignorance of how to read graphs despite being written or conveyed by educated people. If you want a real graph, go to Flip the Script, where they are gathering actual data.

I have toggled the graphs to optimize visually how the virus is spreading. I will justify my selections below.


Select "Scale to Highlight", so we can view the detail of our selected country.

Select "New Cases" because that shows the rate of infection. Anyone who displays "Total Cases" will be aiming to cause panic. Why? To get viewers/readers. To sell politics or whatever they're peddling. We don't know how, when, or if the cases are considered no longer active. That could easily be politicized. New cases, on the other hand, would be difficult to argue with.

Choose "1 week average" because there are a lot of institutions collecting and entering data, and we can probably surmise they aren't all performed exactly the same. This averages out reporting differences.

Choose "Linear" because most of us can intuit what's happening in the graph. Choose "Log" if you can think in exponential terms, which is a rare individual. Anyone showing graphs for public consumption should do "Linear" to maximize understanding.

What do we see? A slow decline. Why is it slow? Probably due to our large population, freedom, and ease of transportation. [See ETA below for new discussion of this.]

How much of a decline? On Day 34, it maxed at 95.8 average cases / million per day. On Day 67, it fell to 70.2 average cases / million per day, which means the rate of infection has fallen 26.7% [UPDATE: Day 69 is at 28.1%]. The rate of change is somewhat less than one percent a day.* Not impressive, but it's dropping.


Another Reason to Select 1-Week Average

Take a look at this graph of New Cases Per Day. What do you notice?


There's a sawtooth pattern. What is its frequency? About a week. This suggests that there are differences in reporting. This doesn't suggest false data, but "spikes" can be misunderstood as something more than what they are.

It is possible that the spikes could be due to patterns in shopping if the nation is more or less regular in their shopping habits, but that would mean that the virus manifests into symptoms at a very regular rate -- not two to fourteen days.

If you look at the the death toll as it changes day by day, you'll see the same weekly sawtooth (this doesn't exclude the possibility of shopping being the cause, but it does suggest that differences in reporting may reveal the culprit of why these patterns appear:



A third possibility for the sawtooth patterns may be healthcare-worker fatigue although that would be strange to see this appear at such regular intervals across the nation, but it may represent a hospital's ability to admit and treat patients. Perhaps there are times of day, or days of the week when a patient receives the best care.


 Death Toll

Some news outlets have used death tolls to indicate spread, which is dramatic and misleading. That number can only go up, which can only lead to anxiety. Once dead, always dead. Ignore any institution who uses this information. Nonetheless, I also looked at New Deaths to see how that's changing.



On Day 30, it maxed at 8.1 average deaths / million per day. On Day 52, it fell to 4.6 average deaths / million per day, which means the death rate has fallen 43%. The rate of change is two percent a day.*

This has fallen quite precipitously. Why? Changes in testing? Health care system? Population better informed (thanks to news / websites / politicians)? Population better prepared to seek medical attention? Something else? I haven't yet seen this discussed. Whatever the cause, it's encouraging.


Misleading

A lot of the anxiety about the virus is caught in a positive feedback loop--not that the result is positive but our tensions rise and we share our anxieties which causes theirs to rise. They share info that causes our anxiety to rise further, etc. What can we do to exit the loop?

Be open to positivity. Be liberal. Avoid rejecting ideas because it doesn't match your tribe's script. Try to understand where someone's coming from. Maybe they are poor. Maybe they need to work for psychological reasons. If we close ourselves off from different opinions, we can do nothing but enter a positive feedback loop.

We can be more careful about language, especially if language is our job. Any time you hear "spike," be wary. The writers (unwittingly?) are fomenting anxiety among readers by using data gathered in a manner that is unlikely to be uniform, but lumpy or spiked. We need to look at what's going on overall. Moreover, each individual has a different immune system and healthiness. Given this, the data is unlikely to be uniform, even should there be perfect data capturing.

If you hear event X "coincides" with a spike on the same or next day, then they are trying to make connections that may not exist. Avoid this writer and possibly the publication or news outlet. It takes time for symptoms to manifest, and time to consider whether it's worth going to the doctor (if they ever do), and time to see a doctor, get tested and get diagnosed. Moreover, how can you tell which event does what? We'd need people to test before and after--not to mention follow whom they come into contact with--to arrive at reliable conclusions.

One news outlet connected a gathering one day with deaths on the next--a connection which should take a week or three to occur, if this were monitored.


Thinking about the Future

One writer proposed testing every citizen. That would make much clear. However, that may not capture the true numbers since one could be infected yet not manifest, so we'd need to test all citizens within one day, and test them all again a few days later. And so on, for a few weeks. We'd know more about the COVID virus this way. Of course, in testing everyone, we might increase the spread.

Also, this is just one of many viruses. Later mutations may not behave the same, so universal testing may be a large expense with little future use.

You could argue that this would resolve the epidemic quickly. Maybe. Assuming that we keep our borders closed until the virus has left the planet (or until we make a vaccine) and assuming that people make themselves easily found.

COVID-19, many conjecture, may be with us for years. What do we do in the meantime? What if another virus appears next year and the year after that? How will we handle these complications? These are questions we will need to consider.

As the weeks progress, we will have more evidence as states stay closed (or people choose to stay at home), and other states open and some re-enter normal life with caution and others with caution abandoned. This graph will change, for better or for worse.*

* The graphs are from yesterday, which is when I wrote this. The rates for today remain about the same, with an uptick in numbers. At the time of writing this, the graphs hadn't been updated. Making new graphs for one additional data point doesn't make sense although, of course, the new data point may look dramatic on the New-Cases-Per-Day graph.







NOTE: Please credit me. I don't own the graphs although I did manipulate them. And I did write this, ideas that occurred to me from reading the graphs, not following news media or talking heads. Yes. I wrote everything on the blog, so it's copywritten. Please follow standard usage. Feel free to quote.

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