Indicators of the coronavirus COVID-19 outbreak development
(A.B. Alyokhin, B.V. Burkynskyi, A.B. Brutman, A.I. Laiko, Z.N. Sokolovska)
Statistical monitor
14.05.2020. No 56.
We continue to publish the COVID-19 outbreak’s IP progress indices in the world and in a number of countries, including Ukraine, according to official statistics as of May 13, 2020 (Fig. 1–4).
Most countries, except Iran (due to continuing, almost 10 days, a high level of new cases in recent weeks), over the past day showed a positive trend of progress (fig. 1).
In China, the level of progress indicator has risen slightly (99,87% vs 99,86 %). The value of the case fatality rates I(TC) and I(CC) hasn’t changed (5.59% and 5,60%, respectively). The forecasted completion date of the outbreak in this country also remained unchanged and is May 13–14, 2020, with forecasted final fatality rate of 5.58%-5,59%. Let’s remind that at the final stage of the outbreak, its movement to the final state is asymptotic, therefore, to the outbreak’s completion date forecast should be treated with due sense. We have almost no doubt that the real completion date of the outbreak in China, even without new cases, will be delayed.
Generally, the outbreaks and pandemics’ ratings in the world, that we are monitoring, are shown in Fig. 5. The countries’ ranking over the past day has not changed.
Fig. 6 shows the dynamics of actual values of both case fatality rates generally accepted in medical statistics and progress indicator IP that we propose. Fig. 7–10 present the dynamics of the actual values of daily growth of the basic indicators of the COVID-19 outbreak in Ukraine and trends that best describe the relevant statistics. The graphs in these diagrams illustrate the development of the coronavirus outbreak in Ukraine until the present time.
Considering the statistical data on Ukraine as of May 13th, 2020, there’s hope on the formation of a peak of new cases (Fig. 7). However, the variability of this daily rate makes it difficult to draw definitive conclusions on this matter. However, we cannot but draw attention to the fact that the number of tests per day is reduced in Ukraine in recent days. As we have repeatedly noted, the number of tests is one of the main factors of formation of statistics on this indicator.
The trend in increasing number of deaths (Fig. 8) still looks disappointing.
The trend in the number of recovered and active cases in Ukraine to date (Fig. 9, 10) can be considered as positive.
In this issue we publish diagrams for coronavirus outbreak in Japan (Fig. 11–15), analogues to diagrams 6–10 on Ukraine, which is far ahead of many of the monitored countries as regards the level of progress and is characterized by specific features in the COVID-19 outbreak development. The aim of such diagrams is to provide a possibility to compare the COVID-19 outbreak in Ukraine and other countries of the world.
Based on the analysis of Fig. 11–15, the following should be noted:
Case fatality rates I(TC) and I(CC), on the example of the outbreak in Japan, demonstrate the behavior close to classical. However, there are some features. It is that case fatality rate for closed cases I(CC) in this country were low initially, which distinguishes favourably Japan from many other countries. However, Fig. 11shows that the fatality rate in Japan isn’t low.
The example of the outbreak in Japan, also clearly shows that in the early stages of the outbreak the fatality rates behave quite chaotically, which significantly limits the possibility (and feasibility) of their use as a tool of analysis. Then, they show a tendency to converge (one “top — down”, the other “bottom — up”) indicating the final value of the fatality rate. That’s the main point of simultaneous consideration (and demonstration) of the trajectories of these indicators’ values change.
The progress the IP, throughout the outbreak’s life cycle, indicates pretty informative the trend towards convergence of the above indicators of fatality, reaching 100% while achieving the same value by both fatality rates, which happens only at the time of final completion of the outbreak._
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Note.
A progress indicator (IP) of 1.00 indicates the end of the outbreak in the corresponding region, i.e. at the time without new infected, current patients are absent, all previously infected have added the lists of recovered and deceased.
Diagram 1 shows the values of the IP progress indicator for all countries of the world taken all together , China, countries of the world with the exception of China and several other countries.
Diagram 2 shows the “leaders” from among the analyzed regions and countries.
Diagram 3 shows the “average”.
Diagram 4 shows “outsiders.”
The terms “leaders”, “average” and “outsiders” are used solely to differentiate countries and regions by the level of the IP epidemic progress index and assign them to different diagrams for easy viewing and visual comparison.
At the time of the outbreak completion, the values of both WHO case fatality rates should be equal.
WHO case fatality rates unable to reflect sufficiently the outbreak dynamics. In contrast, the IP progress indicator accurately and informatively captures changes in the outbreak development.
The forecast for the outbreaks’ completion dates is calculated using a linear trend, determined by statistical data for the last decade of the observation period.
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Source of statistics:
https://www.worldometers.info/coronavirus/#countries
https://www.pravda.com.ua/cdn/covid-19/cpa/
Our publications:
https://www.facebook.com/MATHMODELCOVID19
https://t.me/mathmodelcovid19
Our initiative group and mission:
https://www.facebook.com/ab.alyokhin/posts/117804769862427
Our publications on case fatality rates and indicator of progress:
https://www.facebook.com/ab.alyokhin/posts/105684827741088