Canada saw a significant increase in excess mortality in 2022. While excess deaths in 2020 and 2021 were largely driven by Covid-19, the same cannot be said for 2022. Why did Canada have more deaths than expected in 2022 than in the previous two years?

Excess deaths in 2022 were driven by a variety of factors that all seem to be interacting with each other, according to experts.

Citing data from Statistics Canada, Erik Pickett, actuary and chief content officer at longevity data analytics firm Club Vita, said Canada weathered Covid-19 better than the US and the UK did in the first two years of the pandemic, with 5.7% and 7.5% of excess mortality in 2020 and 2021, respectively. However, the figure rose to 13.5% in 2022, with only half of the excess deaths related to Covid-19. 

“In general, we're seeing sustained levels of excess mortality persisting throughout most of 2022. Maybe it could be explained largely by the Omicron wave at the beginning of the year, but in the latter part of the year there was a large number of excess deaths, not all recorded as Covid.”

The situation was different in the US, where 16% and 17% more deaths than expected took place in 2020 and in 2021, respectively, but excess mortality dropped to 10% last year, Pickett said, citing data from the Centers for Disease Control and Prevention.

“There's a question there of whether we've stopped recording Covid deaths quite as well as we used to be or whether there's something else going on that's contributing to this persistent level of excess death,” he said during a webinar organised by Club Vita on 19 October.

Looking at different causes of death, Pickett noted deaths caused by respiratory diseases “dropping a little bit” when Covid-19 was introduced in 2020. 

Some of these deaths could be displaced by Covid, he said, but concluded that overall, the reductions did not lead to a “wholesale change” of the situation.

Timothy Meagher, vice president and medical director at Munich Re in Canada, queried how accurate death certificates are to indicate causes of mortality. 

He said: “What is the gold standard for accuracy of a death certificate? Interestingly, when you compare death certificates against autopsy, which is pretty good consider as the gold standard for cause of death, there's often a major disconnect up to 50% of times. You've got to be circumspect about death certificates.”

He believed that during the pandemic, due to the “extraordinary disruption to healthcare services”, the administrative aspects of healthcare may have had an impact on the quality of death certificates but he added: “I'm just speculating here.”

Meagher also noted when people are admitted to hospital “with many different diseases”, the issue becomes complicated when filling out death certificates as the cause of death can be “very difficult to be conclusive”.

Meagher argued that long Covid – the long term impacts of the disease after infection – could cause hospitalisations due to organ failures or specific complications to some people, therefore, having an impact on their future mortality. 

He said: “For example, you can have kidney failure, liver failure [or] you can have an intracerebral bleed. These are all well-recognised acute complications and they have a major impact on your mortality and also your long term morbidity.”

However, Meagher explained it is not easy to determine what long Covid means due to different definitions by health authorities. 

For example, the World Health Organization considers long Covid a condition where symptoms last beyond three months of infection. But the National Institute for Health and Care Excellence defines post-Covid-19 syndrome as signs and symptoms that develop during or after infection and continue for more than 12 weeks. 

Meagher added in the US, authorities argue long Covid is not a single condition but is broadly defined as signs, symptoms and conditions that develop and are present for four weeks or more after initial infection. 

“So we've actually have three ongoing quite different definitions of what long Covid is. That's added to a great deal of confusion… There is the array of possible outcomes post-infection that may have an impact on future mortality.”

Dan Ryan, chief research officer for COIOS Health, noted waiting times for surgery in Canada increased to 27.4 weeks in 2022 from 22.6 in 2019. He said the problem with more people dying while on waiting lists predated Covid-19, but the pandemic became “hugely disruptive” to those who needed treatment for other conditions such as cancer: “What we've seen [was that] through the pandemic, the numbers have increased.”

Ryan also pointed to the ‘hidden’ waiting list: “It's those people who either are waiting to be put on the waiting list or may indeed have not yet gone to the healthcare physician or otherwise identified that they have something which really needs to be looked at. So this reticence or difficulty of getting the waiting list means we have a hidden waiting list, which is even more of a perennial problem.”

Meagher agreed with Ryan, describing waiting lists as a feature of the Canadian healthcare system to control costs. 

Issues with hospitals and long-term care facilities not meeting demand already existed before Covid-19 came along, said Ryan.

According to a report published in March by the Financial Accountability Office of Ontario, the growth in elderly Ontarians already exceeded in the number of hospital beds as well as long-term care beds in 2019. Based on projected growth in demand, by 2027-28, the province is expected to have less hospital capacity and less long-term care capacity compared to what it had in 2019-20.

The problem was exacerbated with the pandemic, Ryan said, as a significant number of deaths took place in long term care facilities when the pandemic was first introduced.

“Part of that relates to having to change the whole modus operandi of how you look after people in long-term care facilities. If [healthcare professionals] are moving from one care home to another care home, then it's relatively easy for infections to be spreading.”

Ryan also noted that, based on a survey about the mental health of healthcare working, around half of physicians and nurses said their mental state had become “somewhat worse or much worse” compared with pre-pandemic levels. In addition, more than 80% of Canada’s healthcare professionals felt more stressed at work as a result of Covid-19. 

“The pandemic clearly had an enormous toll on healthcare workers,” said Ryan.

Asked about the correlation between excess deaths and climate change, Pickett said one of the most notable incidents in Canada was a heatwave in British Columbia in 2021, which saw a “big spike in one week’s worth of deaths that really messed up all the scales on our chart”. 

Despite this, Pickett said the annual mortality figure only changed by 1%. 

He believes climate change will have a greater effect on mortality as more weather events are observed around the world, but  at the moment it is “probably not enough to move the needle a lot on the scale that we're looking at the moment for existence”.

Pickett concluded: “We did see excess deaths coming from the heatwave in 2021, but it's not an explanation for all the excess deaths that we've seen.”