We Cannot Gauge CFR from the Diamond Princess cases… yet.

I’ve seen some discussion that we can assume a CFR for #covid around 1 based on the passengers aboard the Diamond Princess. The logic goes like this. “742 cases, 6 deaths, so that’s a CFR of .8. That’s WAY below the 3.4 in China.”

This is problematic because there are six deaths *currently*. Of the 742 patients infected, only 40 have recovered. Assuming a .8 CFR would be no different than arguing there is only a 5% recovery rate. We know that is not true based on China which has had 81,000 infections and more than 60,000 recoveries.

696 of the 742 Diamond Princess passengers are still active. We have no idea what the final resolution of those cases will be. So the death toll is likely to rise.

The upside to tracking those patients as a unique cluster is we know the number will not rise. As a result, the way these cases eventually resolve should be a decent indicator of the actual CFR.

On the downside, they will still likely skew low because these 742 people have been under constant monitoring since their first exposure. They didn’t sit at home thinking they would get better for several days. The care they have received has been more immediate than the average person may get. That may reduce their CFR relative to the general population.

What we do know is that we still can’t declare a CFR of 1 based on the fact that only 6 have died with so many yet to recover.