1/x You'll be hearing a lot about the term "case fatality rate" in COVID-19 discussions. It's the reference indicator often used to compare how lethally bad COVID-19 is relative to influenza & calculated as Covid-19 +ve Deaths / Covid-19 +ve Cases.

2/x The big buzz over the last 2wk is Dr. Fauci's comment in the Mar.27 New England Journal of Medicine that the if we get a better estimate of asymptomatic +ve folks, based on case fatality rate, it may turn out to be as Trump said: like the flu. https://www.nejm.org/doi/full/10.1056/NEJMe2002387#.Xo6isztA3Yd.twitter

3/x Early estimates of COVID-19 ranged from 2-3% but as we are accumulating more data, we're beginning to hone in on it's true cfr & it appears to be around the same number as an early study of Wuhan hospitalized patients at 1.4%, whereas the flu is 0.1%. https://www.nejm.org/doi/full/10.1056/NEJMoa2002032#.Xo6gjoQjLD0.twitter

4/x The COVID-19 cfr of 1.4% vs flu's 0.1% makes COVID-19 10x more lethal than influenza &debunks the notion that they're similar. However, as Fauci said,the # of +ve cases is actually higher than what has been reported due to low testing rates &imprecision in # of asymptomatics.

5/x This past wk there's been a lot of talk about what's that exact # of COVID-19 +ve asymptomatics walking around? A recent Chinese study published in the British Medical Journal estimated it to be as high as 86% of all COVID infections (& we're only testing symptomatic folks).

6/x There's been a lot of pushback on the quality of that Chinese study arguing that it's a gross overestimation because it didn't track all the people in the study to the end to see if they became symptomatic later. https://twitter.com/angie_rasmussen/status/1247608890985873408?s=20

7/x Other studies seem to hint that the asymptomatic carriage rate may be closer to 25-32% of all COVID infections. This is a good thread on that topic: https://twitter.com/EricTopol/status/1241779473336287235?s=20