Factors influencing the COVID-19 daily deaths' peak across European countries

Abstract

Objectives: The purpose of this study was to determine predictors of the height of coronavirus disease 2019 (COVID-19) daily deaths' peak and time to the peak, to explain their variability across European countries.

Study design: For 34 European countries, publicly available data were collected on daily numbers of COVID-19 deaths, population size, healthcare capacity, government restrictions and their timing, tourism and change in mobility during the pandemic.

Methods: Univariate and multivariate generalised linear models using different selection algorithms (forward, backward, stepwise and genetic algorithm) were analysed with height of COVID-19 daily deaths' peak and time to the peak as dependent variables.

Results: The proportion of the population living in urban areas, mobility at the day of first reported death and number of infections when borders were closed were assessed as significant predictors of the height of COVID-19 daily deaths' peak. Testing the model with a variety of selection algorithms provided consistent results. Total hospital bed capacity, population size, the number of foreign travellers and the day of border closure were found to be significant predictors of time to COVID-19 daily deaths' peak.

Conclusions: Our analysis demonstrated that countries with higher proportions of the population living in urban areas, countries with lower reduction in mobility at the beginning of the pandemic and countries having more infected people when closing borders experienced a higher peak of COVID-19 deaths. Greater bed capacity, bigger population size and later border closure could result in delaying time to reach the deaths' peak, whereas a high number of foreign travellers could accelerate it.

Keywords: COVID-19; Healthcare capacity; Modelling; Mortality.

Fig. 1

Histogram of the height of COVID-19 daily deaths' peak per 1 million inhabitants with a fitted log-normal curve. The histogram presents the distribution of height of COVID-19 deaths' peak per 1 million inhabitants across 34 countries. A log-normal curve was fitted to the distribution with a scale parameter sigma of 1.12 and location parameter zeta of 1.38, assuming logarithm of height of the deaths' peak is normally distributed [Normal(zeta, sigma)]. COVID-19, coronavirus disease 2019.

Fig. 2

Height of COVID-19 daily deaths' peak per 1 million inhabitants across countries. The plot presents the height of COVID-19 deaths' peak per 1 million inhabitants across 34 countries, with Belgium having an outstandingly highest peak per population size (>40 deaths per 1 million inhabitants). COVID-19, coronavirus disease 2019.