The number of amputations due to frostbite in Edmonton reached 110 last winter, the highest level in more than a decade, according to new data obtained by CBC News.
But Calgary marked its second consecutive winter of declining frostbite amputations, counting roughly one-third of Edmonton’s procedures last fiscal year.
The frostbite amputation numbers mark a notable shift after years of Alberta’s two major centres following similar trends.
It is not clear what caused the sharp divergence.
But doctors and homeless advocates point to two key differences between the two cities that may have played a role: Edmonton’s aggressive encampment eviction policy, and the use of a more assertive frostbite treatment protocol in Calgary’s emergency departments.
“I do think that houselessness and substance abuse are certainly contributors to it, but I think there’s multiple things that may be contributing,” said Dr. Scott MacLean, an emergency physician at Edmonton’s Royal Alexandra Hospital.
What the numbers show
According to data from Alberta Health Services, the Edmonton health zone saw 110 amputations with a diagnosis of frostbite during the fiscal year of 2023-24.
That’s up from 71 the previous year, and surpasses the previous record of 91 amputations in 2021-22.
The Calgary zone counted roughly one-third of Edmonton’s numbers last year.
The health zones include areas well beyond the two cities. Banff and Claresholm are in the Calgary zone, while the Edmonton zone includes Morinville and Evansburg.
AHS does not release health statistics between one and nine on privacy grounds, arguing that an individual could potentially be identified from such a small group.
Because Calgary had one month in the past fiscal year where the number of frostbite amputations was less than 10 but greater than zero, the annual total is only known to be between 32 and 40.
The sharp divergence between Edmonton and Calgary is unusual, as data going back to 2011 shows that the two cities have largely followed the same trends without any significant difference in annual numbers.
Reasons for the discrepancy are not clear.
Weather data from Environment Canada shows that while Edmonton was slightly colder than Calgary, the two cities had similar winters overall last year.
Edmonton saw 21 days below –20 C last winter while Calgary had 17.
The number of frostbite or excessive cold diagnoses in emergency departments didn’t change much in either zone — up nine per cent to 895 in Edmonton, down 17 per cent to 630 in Calgary.
Enumerating homelessness
Frostbite amputations disproportionately affect people experiencing homelessness. While Edmonton’s numbers rose 55 per cent from the previous year, the increase among unhoused patients was 87 per cent.
More than half of such procedures in both cities last winter were performed on patients recorded as homeless.
While Calgary’s homeless population was significantly larger than Edmonton’s a decade ago, the two cities have found comparable figures in recent counts.
The last point-in-time count — conducted on a single day and including people without shelter as well as those seeking services — was in 2022. Edmonton found 2,519 people experiencing homelessness and Calgary had 2,782.
Both cities conducted their 2024 counts this month, but the results won’t be released for several months.
Another method used in Edmonton is the “by name list” count, which is based on data from agencies and only includes people seeking services. That method counted 4,011 people in July.
Homeward Trust did not respond to a request for comment.
Contentious approach to encampments
Edmonton’s 2023-24 winter season saw a series of court rulings, police actions and public protests over the decision to evict residents of encampments and dismantle the makeshift communities.
In December 2023, a Court of King’s Bench judge granted a request from the Coalition for Justice and Human Rights for a temporary injunction against the City of Edmonton to stop an imminent plan for police to conduct a widespread sweep and dismantling of encampments.
In January, the injunction was removed and an earlier CJHR lawsuit related to encampments was dismissed due to the court’s finding that the group did not have legal standing to represent the interests of people experiencing homelessness.
The decision allowed the city and the Edmonton Police Service (EPS) to move aggressively to dismantle encampments, removing nearly 50 in two weeks.
At the same time, the provincial government launched a navigation centre where unhoused and vulnerable people could receive help accessing services ranging from shelter to acquiring identification to financial assistance. A navigation centre for Calgary was announced in June and opened in July.
Chris Wiebe, counsel for CJHR, said he sees a direct connection between the encampment removals and the spike in frostbite amputations. He said he felt “intense sadness” at the numbers.
“Unfortunately, that’s consistent with what the coalition’s expert witnesses said would happen — that encampment evictions increase the risk of of exposure to cold weather and thus increase the risk of cold-related illnesses like frostbite,” said Wiebe.
He took issue with the line from officials that tents are inadequate shelter in winter.
“Nobody’s saying the tents are enough shelter,” said Wiebe. “They’re clearly inadequate.” But, he said, they provide at least some protection for people unable to safely access shelters, whether due to fear of violence and theft or policies against allowing couples and pets.
Official response
“Any instance where individuals are sheltering outdoors during extreme cold is an emergency,” a City of Edmonton spokesperson said in a written statement.
“While the statistics on frostbite amputations are concerning, they highlight the broader, systemic challenges of homelessness that extend beyond the city’s direct control.”
In statements, EPS and the provincial ministry of Seniors, Community and Social Services both said tents are not sufficient protection from winter, and highlighted that nearly 4,000 people had engaged with the provincial navigation centre in Edmonton.
Both statements indicated that the encampment removal policy would continue this winter.
“Removing people from freezing cold tents to warm shelters does not contribute to an increase in frostbite,” said the ministry’s statement. “Alberta will not tolerate a return to allowing dangerous encampments to remain.”
EPS said that part of the spike in Edmonton’s frostbite amputation numbers “may be due to greater intervention by EPS encampment response teams, who regularly found people needing medical assistance for exposure, hypothermia and frostbite.”
The City of Calgary and the Calgary Homeless Foundation declined to comment on the data.
More aggressive treatment
Another major difference between Calgary and Edmonton is how frostbite cases are treated.
Since 2019, Calgary has used a more aggressive approach, according to Dr. Catherine Patocka, department head of emergency medicine at the University of Calgary’s Cumming School of Medicine.
The approach is based on a protocol developed by doctors in Yukon.
“Looking at the data [of declining frostbite amputations], I certainly find myself wondering if what we’re seeing is the impact of that protocol,” said Patocka.
A key part of the approach is iloprost, a medication that can reduce the risk of amputation in severe frostbite cases. The use of it for frostbite is off-label, meaning it hasn’t received regulatory approval for that particular purpose.
Iloprost has been used in Calgary through a Health Canada special access program, but its use in Edmonton is rare, according to MacLean, the Edmonton emergency doctor who is part of a University of Alberta group studying its use.
“It’s almost never given in Edmonton … whereas in Calgary it’s quite commonly given,” he said.
“When I look at the last three years of severe frostbite in Calgary, almost every case has received iloprost.”
It isn’t known how much iloprost might account for the the discrepancy between the two cities’ experiences with frostbite cases, or how often the use of iloprost avoided the need for amputation. The use of iloprost in Calgary began in 2019, but the city still saw a major increase in frostbite amputations in 2021-22.
To determine iloprost’s efficacy, MacLean and his colleagues have been comparing outcomes between frostbite cases in Edmonton, which did not involve iloprost, with similar cases in Calgary that did use the medication.
He said he expects the treatment to be more widely available to Edmonton doctors this year.
He said the increasing numbers for frostbite and amputations in Edmonton tracks with his own experience in the emergency department.
While MacLean agrees that a tent is inadequate protection from frostbite, and better long-term solutions are needed, he doesn’t see Edmonton’s encampment eviction policy as a good approach.
“I don’t think that taking away limited shelter when inadequate shelter spaces are available has been helpful.”