Math people, need some help here

[Lulu KC]

Without testing, the data on our rates of infection are unknown. But we do know the # of deaths.
Once we get testing going on a large scale (assuming we do), will we probably show a smaller percentage of deaths--due to proportion?
Please be kind, and answer as if I'm in fifth grade--I'm in recovery from a mathphobic childhood. Thanks!

[treestar]

1. Not a math whiz, but I think you are right

The denominator would increase with the testing showing everyone who is infected, regardless of symptoms.

[Sedona]

2. Yeah but what about all the people who have already died without a test?

How do we count them?

[OnDoutside]

3. Were those dead people confirmed positive before death ie

Since there are so few people tested, maybe the death rate is much higher but the death is put down to the underlying illness ?

[dawg day]

4. Or to flu

Or pneumonia.

[OnDoutside]

6. Absolutely, yes.

[defacto7]

5. All numbers are speculative while the disease is still active.

All the calculations can show are trends. All the experts can offer are best estimates. If you are looking for the best estimates this site gives good explanations of the process and figures.

https://www.worldometers.info/coronavirus/coronavirus-death-rate/#correct

https://www.worldometers.info/coronavirus

[lettucebe]

7. I'm math challenged but yes, absolutely, this will bring down the percentage

The more people tested, the lower the death rate percentage will be. We need testing now

[zonemaster]

8. Look at data from a country that tests A LOT - like South Korea.

In a perfect world, you'd test every citizen every day, get the results back in 10 minutes and send out 330 million new, individualized behavior edicts every day. The US is at the other end of that spectrum, unfortunately.

If you just want to get a data-supported characterization of the virus, look at data from a country that's testing the shit out of people, comparatively. That'll certainly be a lot closer, but there will be some factors of arguable levels of influence that may somewhat color one country's results vs. another. Also, as in Italy, you can see that there are some 'non-linearities' involved where factors like how overwhelmed the hospitals are at any one moment, the mean age of the population, the mean accumulated lung damage prior to infections, etc., that can cause models to vary quite a bit, even if you're testing everyone.

[coti]

9. Yes, I do expect the death rate to ultimately go down, long-term.

On a very short-term basis, you can expect the death rate to actually go up slightly as infections have a "head start" on deaths by some days- i.e., deaths will continue for a short time even if infections completely stopped. The "wave" of acceleration for deaths is slightly behind infections.

But, yes, there's a presently a strong selection bias toward severe presentations of the virus, which can inflate the death rate.

[Wounded Bear]

10. All numbers are fluid right now, so best not to focus too much on them...

statistics is like that. As sample sizes rise, the numbers get more accurate.