Excess Mortality in Canada (December 14th Update)
Some housekeeping: Thanks for all the well wishes on my last post. Unfortunately, I remain unwell, and I expect that to continue for the foreseeable future for reasons related to failures of the healthcare system that I won’t get into because it makes me cry. I am hoping to publish a few updates this week, but I do not want to set expectations especially high.
Highlights
While it is difficult to summarize the weekly data in words (as evidenced by the lengthy alt text added to each chart), I can summarize the cumulative data to this point.
Note: This data is subject to change slightly in future updates. The data by age does not add precisely to the data for all ages, partly due to the data for the most recent weeks being missing for some age groups, and likely due to differences in the ways deaths counts are adjusted for delays and incompleteness.
There were 97,773 more deaths than expected in Canada during the period from March 1st, 2020 and August 19th, 2023
The number of deaths in Canada from March 1st, 2020 to August 19th, 2023 was 9.7% above the number expected
There were 26.8% more deaths than expected in Canada from March 1st, 2020 to July 29th, 2023 among those aged 0-44, representing 12,733 deaths in excess of the 47,509 expected in this age group during that period
There were 12.1% more deaths than expected in Canada from March 1st, 2020 to August 12th, 2023 among those aged 45-64, representing 16,982 deaths in excess of the 140,793 expected in this age group during that period
There were 9.2% more deaths than expected in Canada from March 1st, 2020 to August 19th, 2023 among those aged 45-64, representing 40,953 deaths in excess of the 446,860 expected in this age group during that period
There were 8.3% more deaths than expected in Canada from March 1st, 2020 to July 29th, 2023 among those aged 85 and over, representing 30,914 deaths in excess of the 371,814 expected in this age group during that period
A quick note on the data source
With that out of the way, I want to share the provisional excess mortality data updated by Statistics Canada on December 14th. The data can be found here, with methodology detailed here. The vital statistics data underlying these figures is provided to Statistics Canada by the provinces and territories at a significant delay, so the most recent data is very incomplete.
Below is a chart of excess weekly mortality as reported in the most recent 5 updates. As you can see, significant retroactive corrections are made with each update, particularly to data from Summer 2022 onwards. This is important to keep in mind when interpreting recent data.
Weekly Adjusted Deaths and Weekly Expected Deaths
For those unfamiliar, excess mortality refers to deaths in excess of what is “expected”. The methodological information linked above provides details on the way expected deaths are calculated and how reported death figures are adjusted to (somewhat) make up for incomplete and delayed reporting. The following charts shows weekly adjusted deaths and expected deaths in Canada for all ages and by age group from March 1st, 2020 to the latest week of available data, which is August 19th for all ages, ages 65084, and ages 85+, August 12th for ages 45-64, and July 29th for ages 0-44. Note that the scale of the y-axis differs between charts.
The difference between the two figures plotted above is excess mortality. Where the figures above are shaded blue, orange, grey, green, or aqua (meaning deaths exceeded the number expected), excess mortality is above zero. Where the figures above are shaded black (meaning fewer deaths than expected), excess mortality is negative.
And here is weekly excess mortality, or the difference between deaths and expected deaths, by age group:
Dividing the excess mortality by expected deaths calculates percentage excess mortality. For example, 10% excess mortality for a given week means that there were 10% more deaths than were expected during that week. The following figures show weekly percentage excess mortality in Canada, for all ages and for each age group. Note in particular the figures for ages 0-44.
The Cumulative excess mortality for a given week is the sum of weekly excess mortality up to and including that week. It increases after every week where more deaths occur than were expected, and decreases after every week where fewer deaths occur than were expected. The following charts show that nearly 100,000 more deaths occurred in Canada than were expected between March 1st, 2020 and August 19th, 2023.
The following charts represent cumulative percent excess mortality from March 1st, 2020 to July 29th, 2023, broken down by age group and by year. The indicated average of 9.7% means that, among all age groups and in all years during the time period indicated, there were 9.7% more deaths in Canada than expected. I would interpret the 2023 data with caution in light of the delayed data reporting.
The following charts are identical to the chart immediately above this paragraph, but they are specific to each age group. My note of caution about 2023 data still stands, despite the high figure for ages 0-44. While I hope this figure does not further increase upon future updates, I will be very surprised if it does not. The “all years” average” for each age group is the same figure reported in the breakdown of cumulative percent excess mortality by age shown above.
I have several half-finished drafts that I am hoping to post in the coming week, but we shall see. I hope everybody is keeping as safe as is possible.