Belgian COVID-19 Mortality, Excess Deaths, Number of Deaths per Million, and Infection Fatality Rates (8 March - 9 May 2020)

Abstract

Background COVID-19 mortality and its relation to excess deaths, the number of Deaths Per Million (DPM), Infection Fatality Rates (IFRs) and Case Fatality Rates (CFRs) are constantly being reported and compared for a large number of countries globally. These measures may appear objective, however they should be interpreted with the necessary care.

Objective Scrutiny of COVID-19 mortality in Belgium over the period 9 March – 28 June 2020 (Weeks 11–26), using the relation between COVID-19 mortality and excess death rates, the number of deaths per million, and infection fatality rates.

Methods The relation between COVID-19 reported mortality and excess death rates is evaluated by comparing publicly available COVID-19 mortality (2020) and the difference of observed and predicted overall mortality. Predictions are based on weekly averages of historical overall mortality data in Belgium (2009–2019). Deaths per million are evaluated using demographic data of the Belgian population (2020). The infection fatality rate is estimated using a delay distribution between infection and death. The number of infections in Belgium is estimated by a stochastic compartmental model, which uses hospitalisation data, serial serological survey data, and COVID-19 mortality data (2020) for calibration.

Results In Belgium, 9621 COVID-19 related deaths are reported between 9 March and 28 June 2020, which is close to the excess mortality estimated by weekly averages of historical mortality data (8985 deaths). This translates to 837 DPM and an IFR of 1.5% in the general population in Belgium. Both DPM and IFR increase with age and are substantially larger in the nursing home population.

Conclusion Belgium has virtually no discrepancy between COVID-19 reported mortality and excess mortality. Due to this close agreement it is useful to consider the DPM and IFR, which are both age, sex, and nursing home population dependent. Data comparison of COVID-19 mortality between countries should rather be based on excess mortality than reported mortality.