Nov 8, 2020

5 min read

A mathematical model and forecast for the coronavirus disease COVID-19 in Ukraine (Мc)

(A.B. Alyokhin, B.V. Burkynskyi, A.N. Grabovoi, V.A, Dilenko, N.I. Khumarova)

Forecast Monitor

08/11/2020. No F-255.

https://www.facebook.com/ab.alyokhin/posts/196077685368468

This monitor devoted to the accuracy analysis of the weekly component of the Mc consensus forecast, compiled for the period from November 2 to November 8, 2020 and published on November 1 this year. (https://www.facebook.com/ab.alyokhin/posts/194328702210033).

Reminder, that the consensus forecast is an averaging of private forecasts obtained using various models and techniques used by our Working Group in the COVID-19 epidemic forecasting. Consensus forecast in our publications will henceforth referred as Mc.

Along with the consensus forecast, our monitors also include an interval forecast Mi, which based on the minimum and maximum values of particular forecasts.

The results of assessing accuracy of the consensus forecast are showing in table. 1–3.

Table 1 shows the calculated and actual values of the main cumulative indicators of the COVID-19 epidemic in Ukraine for 7 days of the forecast period, the absolute (MAE) and relative (PE) errors of daily forecasts, as well as the average absolute error MAE * and the average absolute error in percent MAPE *, including the same cumulative MAPE * score.

Table 2 shows the same data for similar daily indicators of the COVID-19 epidemic in Ukraine.

Table 3 shows similar data for mortality rates I (TC), I (CC, IP progress indicator, average absolute increase in infected (AAG).

Despite the anomalous values of a main indicators number of the COVID-19 epidemic in Ukraine over the past week, the accuracy of forecasting the baseline indicators was quite high.

The average absolute percentage errors (MAPE) for the main cumulative indicators of the epidemic are at the following level (Table 1):

- total number of infected people — 0.42% (0.27–0.53%) *;

- total number of deaths — 0.58% (0.46–0.74%);

- total number of recovered — 5.49% (4.94–6.28%);

- number of active cases — 3.81% (3.61–4.25%).

(*) Here and below, the worst and best estimates of private forecasts indicated in parentheses.

The mean absolute percentage errors (MAPE) for the main daily indicators of the epidemic are naturally lower and are at a high level (Table 2):

- total number of infected people — 6.69% (5.30–7.89%);

- total number of deaths — 15.45% (15.23–17.81%);

- total number of recovered — 37.93% (34.41–43.26%);

- number of active cases — 174.37% (171.43–179.26%).

The accuracy of predicting the derived synthetic indicators of the COVID-19 epidemic in Ukraine is also very high. The MAPE estimates for these indicators are at the following level (Table 3):

- mortality rate I (TC) — 0.28%;

- mortality rate I (CC) — 5.34%;

- IP progress indicator — 4.93%;

- average absolute increase in infected with AAG — 4.93%.

As you can see, only the indicator of the daily gain of the recovered, and after it the indicators directly calculated on its basis (the number of active cases, the mortality rate I (CC) and the indicator of IP progress) deviated significantly from the forecasted values.

In this regard, we note once again that the behavior of the daily increase indicator in the recovered is significant influenced by the human factor, including the subjective and frequently changed criteria for recognizing the patient as healthy and the prompt decisions of authorized persons. In world practice, for this reason, they often refuse to keep (publish) statistics on the number of recovered and, as a rule, to forecast the dynamics of this indicator.

Last week in Ukraine, abnormally high values of the daily increase in the recovered were recorded, which have nothing to do with the objective regularities of the course of the disease and the recovery of Covid patients, which served as the main factor in the high forecast error of this indicator and indicators derived from it.

This facts illustrated in diagrams 1–12. Indices (“c” or “i”) in the numbers of the corresponding figures indicate the type of forecast to which the corresponding charts belong.

Fig. 1–4 displayed:

- actual trajectories of the main cumulative indicators of the COVID-19 epidemic in Ukraine for the entire observation period;

- calculated trajectories of these indicators for a 28-day forecast period.

Diagrams Fig. 5–8 reflect:

- actual trajectories of the main daily indicators of the COVID-19 epidemic in Ukraine for the entire observation period.

- calculated trajectories of these indicators for a 28-day forecast period.

Fig. 9–12 are given:

- actual trajectories of the main synthetic indicators of the epidemic (the average absolute increase in the number of infected, the mortality rates I (TC) and (I (CC), the IP progress indicator) and the average absolute increase in the infected AAG over the entire observation period;

- estimated trajectory of these indicators for a 28-day (4-week) forecasting period.

Fig. 3–4, Fig. 7–8 and Fig. 11 clearly demonstrate the anomalous behavior of the daily increase indicator in the infected and its influence on the actual trajectories of the indicators derived from it.

Beyond the influence of this factor, the accuracy of forecasts, as usual, is very high.

В целом сопоставление фактических и прогнозных данных показывает, что в Украине наиболее вольготно чувствует себя коронавирус, не сдерживаемый ни властями, ни основной массой граждан страны, что сохранение такой ситуации неминуемо приведет к быстрому коллапсу медицинской системы, признаки которого уже наблюдаются, и к росту не только числа умерших, которое и так растет стремительными темпами, но и уровня летальности от COVID-19 в целом.

In general, a comparison of actual and forecast data shows that in Ukraine, the coronavirus feels most at ease, which not restrained either by the authorities or by the bulk of the country’s citizens. The continuation of such a situation will inevitably lead to a rapid collapse of the medical system, signs of which already observed, and only the number of deaths, which is already growing at a rapid pace, but also the mortality rate from COVID-19 in general.

Sources of statistical data:

https://www.worldometers.info/coronavirus/#countries

https://covid19.rnbo.gov.ua/

Our materials also:

https://www.facebook.com/MATHMODELCOVID19

https://t.me/mathmodelcovid19

Accuracy of our forecasts:

https://www.facebook.com/ab.alyokhin/posts/154698732839697 (Germany)

https://www.facebook.com/ab.alyokhin/posts/142548897388014 (Spain)

https://www.facebook.com/ab.alyokhin/posts/150095069966730 (Italy)

https://www.facebook.com/ab.alyokhin/posts/148450556797848 (USA)

https://www.facebook.com/ab.alyokhin/posts/154364292873141 (Ukraine)