There are at least two important new sources of information about hospitalizations due to COVID-19 now. The New York Times has been posting daily charts of new cases and deaths for many months. It now includes a third chart, "Covid patients in hospitals that day".
This is a new type of data and somewhat different than the typical information seen on cases and deaths. The charts on COVID-19 cases are most often either the cumulative count of all cases since the beginning of the pandemic, or the number of new cases on each day. The data on deaths is charted the same way.
For hospitals, it is most useful for decision-makers to know how close hospitals are to their maximum capacity, because of the danger of running out of beds. Neither cumulative nor daily new numbers will reveal what you truly need to know, for that decision.
"Currently hospitalized" is the data type that supplies that needed information. We see that it differs significantly from both "cumulative" and "daily new" types. Cumulative data never goes down. If the pandemic came to an end, this curve would flatten at the top and stay there; right now it is still climbing.
Chart 1. Cumulative Cases
From the slopes in this chart of the total cases count since March 1, we can see three distinct phases reflecting the growing scale of the pandemic in the U.S.: first the initial wave on the East and West coasts; then the summer spread to more states, and now, with the steepest slope, the nationwide spread.
We have previously seen the very jagged nature of the daily data, as this chart of the daily new cases illustrates.
Chart 2. Daily Cases (Dec. 8)
To better visualize the trend, these charts are typically presented with the 7-day average, to smooth the curve. Here we see that the Thanksgiving holiday period produced a pause in the data, but not the infections, which resumed their climb once the reporting of data became available.
The 'Currently Hospitalized' data contains the people admitted yesterday, but also everyone who is not yet discharged, so it also displays a weekend dip, but a much smaller one. In the covidtracking.com dataset, these numbers were first reported starting on March 18.
Chart 3. Currently Hospitalized (Dec. 7)
This line still reveals an effect of weekend data reporting delays, but a much smaller one. Computing the 7-day average does smooth that out, though we don't really need that in order to see the trend, and we also observe the lagging effect caused by looking back 7 days for computation of the average, in the horizontal separation of the curves. A numerical milestone was reached on December 7 in the numbers currently hospitalized, with the 7-day average surpassing 100,000 for the first time, 100,853 hospitalized. This reflects the most recent 6 individual days of numbers of hospitalized patients, all over 100,000. On December 7, this dataset reported 102,148 hospitalized.
These hospitalization numbers are raw counts, but their impact in terms of policies and readiness is relative to the number of hospital beds actually available. What we need to know is the percentage of beds currently filled, and the projections of future percentages.
For these purposes, HealthData.gov is now releasing these specific measures on a weekly basis at https://healthdata.gov/dataset/covid-19-reported-patient-impact-and-hospital-capacity-facility
All opinions expressed in this blog are solely those of the authors, and do not reflect those of University of Texas Rio Grande Valley, or any organizations of which either is a member.