Provisional deaths and excess mortality in Canada dashboard

COVID‑19 continues to affect communities and families in Canada. In terms of lives lost, the toll of the pandemic should account for both the direct and indirect effects of the virus. It is important to measure excess mortality to better understand the direct and indirect consequences of the COVID‑19 pandemic. Excess mortality occurs when there are more deaths during a period of time than would be expected for that period. The number of excess deaths is measured as the difference between the number of observed deaths and the number of expected deaths over a certain period of time. The Canadian Vital Statistics Death (CVS-D) database is the authoritative source for cause of death data in Canada. The CVS-D is an administrative survey that collects demographic and medical information from all provincial and territorial vital statistics registries on all deaths in Canada.

Statistics Canada is using an approach that has been adopted by other countries to estimate expected deaths. There are number of ways to measure excess mortality and each method has challenges, including how to properly estimate the number of expected deaths that would occur in a non-COVID‑19 context compared to the current counts of deaths. It should be noted that, even without a pandemic, there is always some variation in the number of people who die in a given week. This means that the number of expected deaths should fall within a certain range of values.

Interested users may wish to explore more information on COVID‑19 death comorbidities in Canada, COVID‑19 mortality rates in Canada’s ethno-cultural neighbourhoods and how household size and characteristics matter for COVID‑19 mortality.

This dashboard presents data that are relevant for monitoring the impacts of COVID‑19 on mortality in Canada. The two interactive visualizations within the dashboard feature insights on the estimated number of weekly deaths and weekly death counts from the CVS-D. The data used in this dashboard are provisional, as some deaths which occurred during the reference period have not yet been reported. To address this issue, Statistics Canada has produced provisional death estimates which have been adjusted to account for the incomplete nature of the counts. Provisional deaths are not based on all deaths that occurred during a specific reference period because of reporting delays. The provisional death counts and estimates may not match figures from other sources, such as media reports, or counts and estimates from provincial and territorial health authorities and other agencies.

As the pandemic evolves and the number of COVID‑19 infections recede, the mortality dynamics in Canada will also evolve. Some causes of death may show decreases compared with previous years. For example, less road traffic travel, changes in routine behaviours, as well as reduced influenza activity (due to measures introduced to control the spread of the virus that causes COVID‑19), may have led to decreases in deaths due to causes related to these lifestyle adjustments. In addition, there may be fluctuations in patterns of mortality for certain health conditions that could have been affected by perceived or actual changes in access to health care services for prevention, diagnosis, and treatment of critical health conditions.

With these tools, data users can explore trends in excess mortality. These interactive tools allow users to examine excess deaths by comparing the adjusted estimates of weekly deaths to the expected number of weekly death counts. Comparing provisional death counts and death estimates over time can be useful for understanding trends in mortality. The quality of the weekly adjusted counts is dependent upon completeness of the death data reported to Statistics Canada. Only estimates for weeks where the level of completeness reaches 75% or more are shown. The level of completeness reaches 90% or more for almost all weeks, with a few exceptions. More information on these exceptions can be found in the footnotes for table 13-10-0784-01.

Although useful to signal potential new recent trends in regard to excess mortality, estimates based on weekly data with lower level of completeness should be used with caution as they were found to carry more uncertainty. These estimates are subject to change as the number of reported deaths increase for these weeks.

Users can also examine statistical predictions for what future death values may be by selecting the “prediction interval” feature (located within the legend under the graph).

Excess mortality, which accounts for the direct and indirect impacts of the pandemic, occurs when there are more deaths during a period of time than would be expected for that period. One way to consider whether there is excess mortality is to compare the number of deaths being observed with previous years.

The number of excess deaths is measured as the difference between the number of observed deaths and the number of expected deaths over a certain period of time. Using excess mortality insights to assess the direct and indirect impacts of the pandemic can help to understand when there are more deaths during a period of time than would be expected for that period.

To account for pre-pandemic trends in mortality, including the effects of a growing and aging population, Statistics Canada is using an approach that has been adopted by other countries to estimate expected deaths. There are a number of ways to measure excess mortality and each method has challenges, including how to properly estimate the number of expected deaths that would occur in a non-COVID‑19 context compared to the current death counts. It should be noted that, even without a pandemic, there is always some variation in the number of people who die in a given week. This means that the number of expected deaths should fall within a certain range of values.

Beyond deaths attributed to the disease itself, the pandemic could also have indirect consequences that increase or decrease the number of deaths as a result of various factors, including delayed medical procedures, increased substance use, or declines in deaths attributable to other causes, such as influenza.

Recent key insight: National trends

Prior to the emergence of the Omicron variant of COVID‑19, four significant periods of excess mortality were observed nationally since the start of the pandemic. From March 2020 to June 2020, followed by a longer period of excess deaths from September 2020 to February 2021. There was a shorter period experienced in May 2021, and another coinciding with the emergence of the Delta variant, from July 2021 to December 2021.

Since that time, a period of excess was observed beginning in January 2022. Over the nine-week period starting in January 2022 and ending March 5, 2022, there were 8,959 excess deaths, or 16.2% more deaths than expected. While this corresponded with a period of increased COVID-19 activity—more than 6,985 deaths were directly attributed to the disease—it suggests that other factors might be contributing to the excess. For example, a record number of accidental poisonings (including drug overdoses) were reported in 2021.

Over these same nine weeks, Canada had its deadliest week of the pandemic so far, and most provinces experienced periods of significant excess mortality including Newfoundland and Labrador, Nova Scotia, New Brunswick, Quebec, Ontario, Saskatchewan, Alberta and British Columbia. This differed from previous periods of excess mortality, which were generally characterized by greater than expected mortality in only the four largest provinces.

Nationally, the number of deaths fell within the range of what would be expected had there been no pandemic through the rest of March 2022.

Starting in mid-April 2022, however, a period of significant excess mortality was once again observed until early June. Over the course of these eight weeks, there were 3,799 (or 8.6%) more deaths than expected and at least 2,430 deaths attributed to COVID-19. The provinces that experienced this excess were Alberta, British Columbia and Saskatchewan.

The most recent period of significant excess mortality was observed starting in July 2022 and continued through to the end of the year.

While the first period of excess mortality in 2022 was driven by excess mortality in Quebec and Ontario, the remaining periods of excess mortality were mostly driven by the westernmost provinces as well as Quebec and Ontario. In fact, Alberta and British Columbia had higher than expected weekly deaths through much of 2022, and, while nationally, excess mortality has not been observed in 2023, the two westernmost provinces continue to experience excess mortality.