THIS. IS. ABSOLUTELY. LUDICROUS. How does a top official (the ASH is ranked ~3 at HHS) have the gall to say best estimate of CFR is 0.1-1%??? WHO even said it’s 3.4% this week, others say 1-2.5%. S.Korea is ~0.6% but cases very new- #COVID19 has up to 6 weeks horizon from onset.
2) here is the CFR graph from past WHO report. Also, others agree the ASH’s statement above is bonkers. #COVID19. 
3) A reason you can’t rely on a back-of-napkin calculation of S Korea or any new epidemic area is because the cases are relatively new, and haven’t had full amount of time to resolve to either dead or recovered in each cohort. Unresolved cases means CFR not reliable yet. #COVID19
4) Yes, underdiagnosis would lower the CFR, but there is a competing tug between underdiagnosis vs mortality lag in the time to resolution (death or recovered) of a case over the full time horizon. That’s why many put likely CFR around 1-3%, with variation for HC system. #COVID19
