Excess mortality and mortality due to COVID-19 in Québec for the period 2020–2023

Key messages

This report documents the evolution of excess mortality in Québec since the beginning of the pandemic, and the extent to which excess mortality can be attributed to COVID-19. Excess mortality is defined as the number of deaths that exceeds the number normally expected for a given period. This expected number takes into account past mortality trends, the seasonality of deaths, and demographic changes. It is one of the most recognized approaches for assessing and comparing the health and social consequences of the pandemic.

• There has been excess mortality in Québec since the beginning of the pandemic. Between February 23, 2020, and August 26, 2023, excess deaths are estimated at 12,551, or 5% more than expected. The greatest peaks in excess deaths are observed during the first (February 23 to July 11, 2020) and fifth (December 5, 2021, to March 12, 2022) waves of the pandemic (following the arrival of the Omicron variant), a considerable proportion of which are due to COVID-19.
• The period from September 2022 to August 2023 (high endemicity of COVID-19) is characterized by excess mortality that reached lower peaks, but was more sustained over time, compared to the period of pandemic waves. However, the proportion of deaths due to COVID-19 is lower among excess deaths. This coincides with the return of certain respiratory viruses in the fall of 2022, after low circulation during the pandemic due to public health measures.
• Since 2020, no age group has been spared excess mortality. In particular, the oldest age groups were the hardest hit given their small populations.
• The results for excess mortality by sex show a similar trend between 2020 and 2023.
• According to Statistics Canada, between March 2020 and December 2022, excess mortality in Québec differs favourably from that of other Canadian provinces. Results from the World Mortality Dataset show that the same is true on an international scale.
• The COVID-19 pandemic has upset the historically observed mortality trend in Québec. This report identifies some possible determinants of the excess mortality observed since the beginning of the COVID-19 pandemic. These determinants will be the subject of further work.