Games with Models, 6/25/20 Data


The story of today’s COVID-19 data release for RI is one of revision.  Numbers came in above my projections, but that’s largely because earlier data was revised up.  So, the drop in hospitalizations would have made this the first day be below 100 COVID-19 hospitalizations since the epidemic ramped up, but yesterday’s number was revised up enough to pull that target farther away.  Interestingly, the peak number was again revised down, now to 375.

Putting revision aside, however, the news is good.  After two days with new cases above 50, today’s report shows only 40 new cases, despite 3,101 tests.  Other numbers remain within range of recent fluctuations, with a downward trend over time.

It’s been a while since I explained my hospitalization chart, so here’s the summary:

The chart shows reported and projected hospitalizations of people testing positive for COVID-19.  The thicker red line is the latest data.  The other lines are prior projections, with the darker lines being the most recent.  The dashed red line shows the projection on the day before the state switched from counting only people in the hospital because of COVID-19 to counting anybody in the hospital who has tested positive, no matter why they’re there.  The dashed blue line is my first projection, made on April 16.

The red dot on the thick red line is the peak.  The big yellow dot is today’s actual number, and the large green dot is the projection for tomorrow.  The smaller dots show those three numbers for the earlier projections.

Thus, for example, you can see that throughout May, my next-day projections tended to be more optimistic than what was actually reported for that day, and revisions have moved the line up from there.


(See here for my original methodology and here for a subsequent modification I made.)

Projections versus actuals (date of report).

  • Cases:
    • Projection for 6/25: 16,646
    • Actual for 6/25: 16,640
    • Projection for 6/26: 16,679
  • Hospitalizations:
    • Projection for 6/25: 97
    • Actual for 6/25: 103
    • Projection for 6/26: 98
  • Deaths:
    • Projection for 6/25: 914
    • Actual for 6/25: 920
    • Projection for 6/26: 922