App.JackPrior.Org now has the ability to adjust the time window of social distancing used in forecasting.
For any particular country you want to use the “Growth Rate” button to view the rate at which the daily growth rate is dropping and choose the window that best represents the country’s current social distancing practices for use in forecasting future behavior.
Looking at China’s case growth rate, their steep decline occurred between February 6th and March 14th and where their case growth rate dropped at a rate of 17.5% / day from 20% to 0. 003% in ~37 days.
Massachusetts has nearly twice the number of total deaths per total hospitalizations than the next closest states on this metric. Daily Deaths and Hospitalizations are nearly equal in MA while in the remainder of the country hospitalizations tend to fall clearly above the rate of new deaths. Some hypotheses as to why this could be the case include treatment of nursing home patients outside of hospital settings or more deaths at home than in other states. See article from the globe on the slow drop in hospitalizations for MA.
With a few more recent data points and corrections compensating for the data gap in the Covidtracking.com feed the forecasted death curve has flattened considerably and does not show the crossover forecasted a few days ago.
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.