International Differences in COVID-19 Mortality: Some Reflections on Diversity in Data Collection Systems

Daily counts of COVID-19 deaths have quickly become a key figure to monitor the current unprecedented health crisis. Contrasting the total number of deaths attributable to COVID-19 is one reliable way to engage in international comparisons. Such comparisons require statistical information that is harmonized and standardized. However, such data are not readily available, as the urgency of the situation has led to substantial variations in the data collection process across countries. After highlighting the main factors that may create international differences, we analyze and compare COVID-19 death counts for 20 countries, relying on well-documented age and sex COVID-19 death tabulations available in the “Demography of COVID-19 deaths” database (https://dc-covid.site.ined.fr/en/). Selected examples are provided to illustrate the variety of definitions and data collection procedures regarding COVID-19. We discuss the importance of understanding the characteristics of data sources when dealing with imperfect statistics