Retrospective Characterization of the COVID-19 Epidemic in Four Selected European Countries Via Change Point Analysis

The focus of this contribution is to show how the course of the pandemic can be retrospectively investigated in terms of change points detection. At this aim, an automatic method based on recursive partitioning is employed, considering the time series of the 14-day notification rate of newly reported COVID-19 cases per 100,000 population collected by the European Centre for Disease Prevention and Control. The application shows that the pandemic, at the individual country level, can be broken into different periods that do not correspond to the common notion of wave as a natural pattern of peaks and valleys implying predictable rises and falls. This retrospective analysis can be useful either to evaluate the implemented measures or to define adequate policies for the future.