As the countries and states start to move to reopen, the metrics by which these decisions are being made are not clear and not consistent.
Each region is going through an “S-Curve” of initial exponential growth followed by a flattening brought on by social distancing. Although many regions are beyond their peak, the degree to which they have moved their daily counts downward, and how fast that is happening, varies greatly.
We don’t want to move back into a burning building.
The Mayor’s office updated the way it reports data to track it back to the date of initial symptoms rather than when the case was confirmed. Previously case reports had gaps and jumped up intermittently. This data also gives detailed daily data going back to the 1st reported case on 2/28.
It is surprisingly hard to do things in R that are easy in Excel, but at least now it is automated using data from covidtracking.com. This is hot of the press and needs debugging and sensitivity analysis. I am not an epidemiologist and am just looking for simple patterns to extrapolate. Some of these projections seem unreasonable, or perhaps just depressing. In particular, the extrapolations for deaths seem too high for Massachusetts at the moment.
Until April 8th Newton had been following a relatively smooth trajectory of initial post-social-distancing slowing of Covid-19 cases similar to that see in the US. On that day the Mayor announced that ~68 Covid-19 cases had been detected in a local nursing home, adding 39% to Newton’s then total of 178 cases.
Information on Massachusetts Hospital Admissions is available on the Mass.Gov COVID-19 Cases, Quarantine and Monitoring website. The growth rate* in daily admissions has been declining exponentially over time since social distancing was implemented.
As countries around the world have implemented social distancing, they have seen an exponential decrease in their daily case growth rates, each likely reflecting their distancing practices. This pattern can be used to project estimates of how cases and deaths will progress in the US in the coming weeks and months.