Since October of last year, COVID-19 fatalities have nearly doubled, according to the Public Health Agency of Canada (PHAC) numbers, and January 2022 saw the highest rate of excess mortality in the country after Omicron became the dominant strain.
According to Statistics Canada, the excess death rates decreased in the months that followed. But an infectious disease expert warns the true magnitude of excess mortality may be getting hidden by uneven and insufficient reporting on fatalities across provinces, leading to premature conclusions about the actual national COVID-19 mortality trends in Canada.
A recent report from Statistics Canada shows a decline in excess mortality rates after peaking in January 2022. But with the delay in death reporting, especially during the Omicron period, these provisional numbers are likely to rise as various provinces revise their death numbers for July and August, according to an analysis by a grassroots organization.
“It is important to understand that a number of provinces haven’t yet reported all their numbers or have done little reporting after January,” Tara Moriarty, an infectious disease expert at the University of Toronto and the co-founder of COVID-19 Resources Canada, a grassroots initiative, told CTVNews.ca on Thursday.
Excess mortality is reported when there are a more significant number of actual deaths than estimated over a given period of time and helps us understand the direct and indirect impacts of the pandemic by comparing the number of fatalities over previous months. These numbers peaked after the emergence of Omicron in November last year, as it became the dominant strain in the region.
When comparing estimates across different provinces, the data from StatCan showed an uneven distribution in excess mortality estimates. But given that a fraction of total deaths is reported by certain provinces, the total excess deaths in Canada during the Omicron period could be much higher.
The analysis is based on the methodology that the U.S. Centers for Disease Control and Prevention (CDC) uses to estimate excess deaths when the death reporting is incomplete.
Moriarty said that some provinces prioritize reporting deaths in older age groups over younger age groups and update numbers for younger demographic weeks later. So, it is likely that there could be a period of excess deaths followed by a period of mortality deficit. This phenomenon, known as the mortality displacement, has occurred in every COVID-19 wave, Moriarty said.
There is a “strong probability” that excess mortality in July and August could rise “dramatically” for provinces such as Quebec, Moriarty said. “This could be related to the healthcare access crisis and the waning of the COVID-19 vaccine. But this is speculation.”
Quebec has been the gold standard for complete, fast, and timely reporting of severe COVID outcomes. But the province has not done any reporting on younger age groups for the current period so the excess mortality for the Omicron period is largely for people over the age of 65.
Moriarty said the trend in Quebec is an early indicator that there will be a big increase in excess mortality once the numbers on the younger demographic are updated for the Omicron period, and this means that the numbers will go up for the rest of Canada as well.
The excess mortality rate reporting is also slower than COVID-19 updates. And COVID-19 numbers are still getting updated from the first wave of 2020 for some provinces.
Every province is a bit different when it comes to reporting numbers on COVID-19 and many have stopped reporting these on a regular basis.
For example, the two westernmost provinces, Alberta and British Columbia, report excess mortality in younger age groups faster than Quebec. But there may be additional factors such as substance use contributing to the death numbers. Starting in early April, British Columbia reported all deaths within 30 days of a positive COVID-19 test, regardless of the cause of death which results in an overestimation of deaths in B.C.
According to StatCan, additional factors such as increased use and delayed medical procedures/diagnostics could be indirect impacts of COVID-19 itself, including for those under 45.
Nunavut and Northwest Territories stopped publishing COVID-19 updates on April 11 and June 13 this year, respectively. While some provinces have reduced the number of times this data is published. For example, from June 30 this year, Saskatchewan started publishing monthly COVID-19 updates, instead of weekly. Some provinces such as Prince Edward Island, Manitoba, or New Brunswick have not reported since 2021, so the provisional excess deaths may be far from the real numbers.
