Why are COVID-19 deaths not rising at the same rate as cases?

An interesting chart here – looking at the relationship between confirmed cases and deaths (different scales). As cases have risen over the last few weeks, deaths have not risen at the same rate – why?

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Here’s a few reasons why things appear to be different this time around.

What about the Case Fatality Rate?

The CFR simply compares the number of confirmed cases against the number of deaths. It’s a pretty blunt measure as it doesn’t necessarily make any allowances for time lag, but it may give us a feel for how things have changed.

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The CFR isn’t a very helpful measure when testing rates are low. In the early days of the outbreak, even people displaying all the symptoms were not being tested, and so the number of cases was significantly under represented in the official ‘confirmed cases’ count. As a result the CFR (in this case) is pretty meaningless.

Part of the reason for the high numbers in the Republic back in June was the lag between cases and deaths. In June the cases had fallen substantially, but deaths had not yet fallen to the same degree, so the ratio of deaths to cases was very high, in fact on some days the number of deaths was greater than the number of newly identified cases.

By the time we got to August, testing was high, cases were high, and deaths were low, meaning that the CFR was well below 1%.

Let’s have a look at the overall picture on the island on the 13th of September.

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So, as long as the number of deaths is not increasing substantially then we should see this as good news, but how long will this last?

I don’t like to make predictions, but it’s pretty much inevitable that as long as cases are going up, deaths will be heading in the same direction. Of course, it’s possible that cases could only increase in younger, healthier people – but viruses like to spread – and that’s what they’ll do.