A thread about COVID-19 severity rates and what actual data are telling us about our experts' opinions and model assumptions. /1 @LarrySchweikart @TheLastRefuge2 @SHEPMJS @OBgynFl
Severity rates fall into three main categories: [1] Hospital admission (so severe it leads to admission to a hospital). [2] ICU Admission (more severe as it leads to admission to the Intensive Care Unit at hospital & ventilator probably). [3] Fatality rate (most severe) /2
These severity rates and opinions are what have been alarming people the most. Don't get me wrong, the contagion rate is alarming, but mainly because of what expert assumptions have been for models regarding severity. /3
I've been looking for data on these rates, but hospital and ICU admission have been somewhat hard to find. Today I was able to combine three different sources and be able to compare real data to expert assumptions. First from Independent - 3/25 - actual data on severity in NY: /4
"An update on New York state numbers shows 12% of active Covid-19 cases have been hospitalised for the virus..." /5
independent.co.uk/news/world/ame…
independent.co.uk/news/world/ame…
"... About 3% of cases are in the ICU, which is the area of main concern for people who become infected because that is where the patients need ventilators." /6 independent.co.uk/news/world/ame…
Today - 3/26 - CDC published a corrected article from last week. It concerned 2449 cases studied through 3/16 in US where they gave range estimates for severity rates - they didn't have actual data. /7 cdc.gov/mmwr/volumes/6…
But their range estimates for severity were significantly higher than what NY is experiencing. If you take the median of the range, it was over 100% higher in each case than the NY actual data. /8
For hospital admission rate, NY is 12% but CDC had estimated a median of 26% (range 20.7%-31.4%). For ICU admission rate, NY was 3% but CDC had estimated median 8.2% (range 4.9%-11.5%). /9
For fatality rate, NY data as of 3/26 was 466/38977 or 1.2% (according to worldometer). CDC estimate was 2.6% (range 1.8%-3.4%). /10 worldometers.info/coronavirus/co…
Most people tracking this believe the fatality rate will drop further as we better understand the denominator (how may cases are never reported), coupled with new therapies that improve outcomes and reduce avg hospitalization rate and days required in hospital. /11
I think these are the numbers we all hope and pray will continue to improve, as well as our attempts to reduce the contagion by all the distancing and hand-washing, etc. It's important we keep this in perspective. /12 End 
