This Chinese study used 28-day mortality rate. https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30079-5/fulltext https://www.thelancet.com/jo

This Chinese study used 28-day mortality rate. https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30079-5/fulltext https://www.thelancet.com/journals/lanres/article/PIIS2213-2... The best measure will be something of this sort, with a sufficient duration to catch most of the fatalities.