With Saturday’s report not yet in, it is clear that daily reported new cases of Covid-19 disease continue to fall sharply. The 14-Day average on Feb 12th of 1989 is lower than any other day since Nov. 13th. The 7-Day Test Positivity rate reported by Frankfort of 6.95 is also falling rapidly and is the lowest since Nov 5th. (See graphic below.) Baring an unexpected high number of new cases tonight, last week will be the 5th week in a row in which cases have fallen progressively. Reflecting the decrease in new cases, hospital and ICU utilization is going down modestly, but hospital utilization remains very irregularly reported day-to-day. All of this is truly good news. However, at the rate of new-case decline since the beginning of 2021, we will not drop below 4-digit daily numbers until the beginning of April. Since what we are doing now in terms of prevention is clearly working, and if we do not slack off as a community, we should be able to do better. However, that will not happen until the reciprocal public health obligations of the individual and their community is recognized and reinforced.
[Note that since by definition all confirmed cases of Covid-19 have a positive test, and reciprocally that having a positive test defines a case, we expect these two numbers to track each other very closely. Recall also that the number of new cases added to the state’s aggregate total of cases have duplicate individuals removed. I do not know if this is the case for the viral RNA tests that the state uses to calculate its Test Positivity Rate. In any event, it is not clear to me that the Positivity Rate tells us any more about the prevalence of disease in the community than raw case counts. Neither represents a random survey of the community. It is generally accepted that large numbers of individuals contract Covid-19 but are not counted because they were asymptomatic, lacked access to a healthcare system, or for any other reason were never tested.]
New reported cases of Covid-19 are falling sharply after the record numbers related to the December and New Year holidays. It is both logical and reasonable to assume that adherence of public health measures had predictable effects on the recovery. As expected, reported deaths lag cases by at least 2 to 3 weeks for both medical and administrative reasons. Should deaths not begin to fall more sharply we will need to explore possible reasons why. The following graphic compares the 7-Day averages of new cases and deaths as of February 4.
This data visualization can be explored on the KHPI Tableau Public website along with the full portfolio of updated interactive data displays. Without averaging daily reports over either 7- or 14 days it is not possible to reliably discern short term trends.
Additional commentary will be added after Saturday’s report.
Peter Hasselbacher, MD Kentucky Health Policy Institute 4 February 2021
Wednesday evening’s announced numbers extend the trend of new Kentucky cases decreasing. This is evidenced by simple plots of daily cases and cemented by the falling of both 7-Day and 14-Day rolling averages. Based on available data, the Test Positivity Rate as calculated by our Public Health Department is falling in parallel. Even better, both rolling averages are falling away from the exponential growth trendline on semi-log plots suggesting a plateau of new cases if not better. Weekly new cases per week are on track to be much less than the last 4 weeks, but January will likely still be the worst month so far by perhaps as much as 5000 cases.
For deaths however, January continues to be the cruelest month. With 47 new deaths reported yesterday, the total of 880 so far for the month has already set a new record compared to the 754 in December. In my opinion it is too early to tell what is happening to the numbers of people entering hospitals because the day-to-day reported numbers vary dramatically. It is in hospitals and nursing homes that most of the recognized Covid-19 deaths occur. I have begun calculating the daily number of new additions to the reported “Ever Hospitalized” or “Ever ICU” counts using the same logic I use to count new cases and deaths. This takes much of the volatility away. Since mid-January fewer new people are being hospitalized. Nonetheless it is fair to say our hospitals are still working very hard. Despite that burden, some hospitals are taking on the workload of immunizing people against the virus!
As of the end of the week on January 23d, the jagged sawtooth profile of tall daily peaks of followed by deep dips of new cases over weekends and holidays persists, but the peaks are not as high as in early January and our 7-Day and 14-Day averages are back down to about where they were in early December. The number of new cases weekly has been dropping for the past three full weeks. To the extent that Test Positivity Rates are an indicator of community epidemic spread, they remain high but have been trending downwards over the past week. These are all good signs, but we would all like to see a decrease in new cases at this time of rapid epidemic spread nationally and the emergence of new strains of the virus whose impact in the USA remains to be determined. (It will also be reassuring news to learn that the state’s broken case-reporting pathway from its testing vendors had been repaired.)