Question:
So far in 2020, has COVID-19 increased the overall level of mortality in Canada?
Answer:
The answer is yes, but not necessarily for all provinces. And, the full extent isn’t currently known. We explored the same question in an article released in early May. At that time, there was a near total absence of data being released regarding the overall number of deaths in Canada so that the daily reported COVID-19 deaths could be put into context. However, even without this data, it seemed clear that the number of deaths had been elevated in Quebec and Ontario due to COVID-19.
Shortly after our May article, Statistics Canada did a special release regarding weekly deaths by province to the end of March 2020, with comparators from prior years; however, Ontario was a notable exception. The exclusion of Canada’s largest province and the fact that data only extended to the end of March, meant that only limited insights could be gained. A much better assessment of the impact in Quebec has become possible over the past month as the Quebec statistical agency (the Institut de la statistique du Québec) began releasing data on weekly deaths in the province, with the latest update covering up to May 23rd. And, on June 19th Statistics Canada provided an update covering weekly deaths to May 2nd (Ontario was again absent) – the update highlighted that only Quebec, British Columbia and Alberta showed clear evidence of excess mortality over the period, however Statistics Canada believes that the increase for Alberta is due to factors other than COVID-19.
The charts below show the latest weekly death data available for Quebec and British Columbia in the same format as that used by Club Vita UK during the pandemic to visualize:
- how overall weekly deaths (top of each bar) compare to the average deaths for the corresponding week over 2015 to 2019 (purple dashed line),
- if COVID-19 deaths (the dark blue shaded area of the bar) explain all of the excess deaths, and
- if there is evidence of higher deaths indirectly related to the pandemic (whether the lighter blue bars are above the purple dashed line).
Source: Government of Canada, Coronavirus disease (COVID-19): Outbreak update. Institut de la statistique du Québec, Weekly number of deaths in Québec, 2010–2020.
We see from the Quebec chart that in late March, after tracking quite closely, the number of weekly deaths in 2020 began to exceed the average for prior years. In late March and early April, it appears that mortality was increased due to indirect effects of the pandemic and/or early COVID-19 deaths not being fully captured. From late-April onward it looks as if excess deaths have been almost entirely attributable to COVID-19. Over the last seven weeks shown, Quebec’s total reported deaths have been 49% higher than the average for the corresponding weeks over 2015 to 2019.
The chart for British Columbia shows a very different story than that for Quebec. There is a sharp increase in weekly deaths in British Columbia for the week ending March 21st, with the total weekly deaths then trending downward over the following weeks toward the historical average – throughout these weeks, reported COVID-19 deaths were very small in relative terms (1.8% of total deaths). It seems odd that this spike in late March occurs in the week following the first reported COVID-19 death and suggests that COVID-19 deaths may be significantly underreported in British Columbia and/or there may be some other underlying data issues. Regardless, the level of the excess deaths is significantly lower than that for Quebec.
A key remaining question is:
How do 2020 weekly deaths for Ontario compare?
What do you think?
Please post your questions in our Friends of Club Vita discussion group on LinkedIn.