COVID-19: Spatial Analysis of Hospital Case-Fatality Rate in France

When the population risk factors and reporting systems are similar, the assessment of the case-fatality (or lethality) rate (ratio of cases to deaths) represents a perfect tool for analyzing, understanding and improving the overall efficiency of the health system. The objective of this article is to estimate the influence of the hospital care system on lethality in metropolitan France during the inception of the COVID-19 epidemic, by analyzing the spatial variability of the hospital case-fatality rate between French districts (i.e. French departements). The results show that the higher case-fatality rates observed by districts are mostly related to the level of morbidity, therefore to the overwhelming of the healthcare systems during the acute phases of the epidemic. However, the magnitude of this increase of case-fatality rate represents less than 10 per cent of the average case-fatality rate and cannot explain the magnitude of the variations in case-fatality rate reported per country by international organizations or information sites. These differences can only be explained by the systems for reporting cases and deaths, which, indeed, vary greatly from country to country, and not attributed to the care or treatment of patients, even during hospital stress due to epidemic peaks.