Forecasting by Analogy: A Parallel between the Trend of Confirmed COVID-19 Deaths in the Winters of 2022/2023 and 2023/2024 in Italy

Abstract

We studied the weekly number and the growth/decline rates of COVID-19 deaths in the period October 31, 2022 – February 9, 2023, in Italy, finding that that COVID-19 winter wave reached its peak during the three holyday weeks extending from December 16, 2022 to January 5, 2023, and it was definitely trending downward, returning to the same number of deaths of the end of October 2022, in the week February 3 – 9, 2023. During this period of fifteen weeks, that wave caused a number of deaths as large as 8,526. Its average growth rate was +7.89% deaths per week (ten weeks), while the average weekly decline rate was -12.32% (five weeks). Currently, Italy is experiencing a new COVID-19 wave, with the latest six weekly bulletins (October 26, 2023 – December 14, 2023) showing that the deaths have climbed from 148 to 322. The weekly growth rate has risen by +14.08% deaths, on average. In the hypothesis that this 2023-2024 wave have a duration similar to that of 2022-2023, with: i) a comparable extension of both the growing period and of the decline period and ii) similar growth/decline rates, a prediction can be cast regarding the number of COVID-19 deaths in the period November 2023 - January 2024. They could reach the amount of 4100-4200.