What the analysis of causes of death in France in 2020 reveals about the impact of the Covid-19 epidemic (preprint)

ABSTRACT

Context In 2020, the French population lived under the threat of the Covid-19 epidemic, which would allegedly cause an exceptional excess mortality rate. Mortality data by cause of death for the year 2020 are now available. These data allow us to quantify and qualify the impact of the epidemic. This analysis presents the evolution of the main mortality indicators by cause and by age group. It is intended to demonstrate how 2020 was an exceptional year. Materials and methods: In France, causes of death are labeled according to the International Classification of Diseases (ICD-10) based on medical death certificates. The study focuses on aggregated data for the year 2020 as well as complete data from 1979 to 2017 available online. To estimate excess mortality by cause of death, mortality data were standardized to 2020 to take into account changes in the age structure of the population. Results: The year 2020 is marked, on the one hand, by the introduction of "Covid-19" as a cause of death, which accounts for 10.4% of deaths; and, on the other hand, by a strong downward trend in most other causes of death. Discussion: In 2020, we show that the overall number of additional deaths due to the Covid-19 epidemic is paradoxically lower than the number of deaths caused by this disease. According to official sources, the number of Covid-19-labeled deaths is nearly 50% higher than the number of additional deaths. Besides excess mortality in 2020 being modest compared to other years that saw health events and it affecting only individuals over 65 years of age, what could explain that this disease has caused more deaths than additional deaths? This analysis shows that the emergency implementation of the "Covid-19" classification led to many biases. A significant number of deaths, usually labeled for other major causes (e.g., neoplasm, circulatory system diseases) were, in a way, transferred to this new label. This analysis of mortality by cause of death provides quantitative answers to the overestimation of the impact of the Covid-19 epidemic in France.