COVID-19 fatality rate is dropping rapidly in Florida


There’s a lot of hysteria going on about the increasing number of cases and rising positive test rates. The positive test rate is meaningless since we know that negative results do not all get reported. The cases themselves are also meaningless if the majority are asymptomatic and do not lead to commensurate increases in hospitalizations and/or deaths.

June 10 was a big day for Alachua County because 90% of a group of migrant workers tested positive for COVID-19. A rapid rise in positive tests nationwide also started on that day. Using the Florida Department of Health line data (July 10 update) to compare the two weeks before and after June 10 shows an increase in cases of 189% (14,514 to 41,990) state-wide. However, cases requiring hospitalization only rose 46% (1,687 to 2,458), and cases resulting in death only rose by 20% (352 to 422).

This graph does not include the number of deaths and hospitalizations reported on the various dates; it shows how many of the cases that were reported on each date were hospitalized or died, as of the July 10 data file (which covers all Department of Health data through July 9).

Florida’s line data does not exaggerate the number of cases because it includes one line per person. It also shows whether or not that person was hospitalized or passed away (but not the date of either). Using this data allows a comparison of cases to hospitalizations and deaths without worrying about a specific lag time for the disease process. The graph includes the entire state instead of Alachua County because the county didn’t have enough COVID-19 hospitalizations or deaths over that period to make the data meaningful.

Although the data file goes through July 9, we limited the graph to two weeks before/after June 10 because newer cases after June 23 may not have resolved. Note that hospitalizations and deaths are on a secondary axis; otherwise the increases would not be visible at the same scale as cases. The secondary axis is scaled to have hospitalizations start at the same level as cases for easy comparison.

The overall case hospitalization rate dropped from 11.6% in the 2 weeks before June 10 to 5.9% in the 2 weeks after June 10, and the case fatality rate dropped from 2.4% to 1.0%. For people under age 65 (80% of the state’s population), the case hospitalization rate dropped from 7.8% to 3.9%, and the case fatality rate dropped from 0.5% to 0.2%.

The disparity between the surge in cases and the relatively flat hospitalizations and deaths are partly due to the change in demographics: the median age dropped from 40 to 35, and the percent of cases under age 35 increased from 40% to 50%. (This disparity is even greater for Alachua County, where the percent of cases under age 35 jumped to 80% after June 10.)

Even without the demographic shift, the overall case fatality rate, even for those 65 and over, seems to be improving. The graphs below show the percentage of daily cases in the FDOH line data that later died, regardless of death date (i.e., the graph shows the percentage of people who tested positive on each date who later died). The overall rate has dropped dramatically since the start of May. The 65+ rate has been dropping since mid-April and started dropping even faster after May 27. Note that these graphs stop at June 23, allowing over two weeks for the cases to resolve.

Florida moved to Phase 1 reopening on May 4; the charts above clearly show that, while the number of cases has increased, the death rates have steadily declined since around that date.

July 11 Update: Those complaining about only looking at two weeks on either side of June 10 (i.e., 5/27-6/23) clearly do not understand the available data or how long the COVID-19 disease process takes (up to three weeks to either recover or pass from the illness; today’s report of 98 deaths in Florida includes deaths attributed to cases as far back as May 17). If we look at three weeks on either side of June 10, the later cases have not resolved, so the disparity between the case growth and hospitalization and death growth is even greater: 367% increase in cases (19,752 to 92,279), 63% increase in hospitalizations (2,521 to 4,101), and 16% increase in deaths (574 to 663). Here’s the updated graph (note the different scale from the graph above).