VANCOUVER - Tens of thousands of Canadians left the country last year for non-emergency medical procedures, the Fraser Institute says, but some health experts are challenging the way researchers at the think tank crunched the numbers in its new study.

The Fraser Institute released a report on Wednesday suggesting 45,619 people sought health-care services abroad in 2015 and pointed to wait times as the principal culprit.

"We have some good data from physicians that point to a general estimation of how many Canadians are travelling abroad," said Bacchus Barua, a senior analyst of health policy at the Vancouver-based institute.

The study used results from the Fraser Institute's annual survey asking physicians to assign a percentage to the number of their patients who reported receiving treatment abroad. Those values were then applied to the total number of medical procedures carried out in Canada, as recorded by the Canadian Institute for Health Information.

About 45,000 Canadians who sought out-of-country care in 2015 make up about one per cent of the patients of those physicians who responded to the survey, the document says.

The results indicate there was a slight decrease in 2015 from the previous year when an estimated 52,513 people left the country for medical treatment, but a jump compared with the 41,838 in 2013.

Valorie Crooks, a health geographer at Simon Fraser University in Burnaby, B.C., challenged the findings, describing the numbers as inaccurate because of the lack of any definitive record of how many Canadians cross the border for treatment.

"Surveying a limited number of specialists to get some information on Canadians accessing care abroad actually really doesn't reflect a true sense of Canadians' involvement in medical tourism," said Crooks.

Barua acknowledged the imperfection of the study's research methods, but described the approach as "the best estimate we have."

Crooks said there are many reasons people might receive treatment outside Canada, from immigrants returning to their country of origin because of a family support network, or so-called snowbirds who flock to warmer climes over the winter and may access health care abroad out of convenience.

"We know that Canadians are going abroad (for treatments), so the Fraser Institute telling us this is happening is not new," she said.

The study came out days after Republican presidential candidate Donald Trump took a swipe at the Canadian health-care system during a town-hall debate with Democratic challenger Hillary Clinton in the United States. Trump said when Canadians need a big operation they go to the U.S. because of what he called a "catastrophic" Canadian system.

Ron Labonte, a scholar of health sciences, also critiqued the methodology of the Fraser Institute's report, calling the findings "really quite a leap in terms of an estimate," before describing the number of medical tourists from Canada as very small.

"The whole issue of medical tourism, or Canadians leaving the country, is a bit of a tempest in a thimble," said Labonte, who teaches at the universities of Ottawa and Saskatchewan, and at Flinders University of South Australia. "It's not something that I think puts into serious question the Canadian health system.

"Even looking at the Fraser Institute's numbers. ... One per cent. One in 100. Even that's not terribly large."

Barua stood by the results, calling for wait times to be considered in the discussion on health-care reform.

"Whether it's the chief motivator for why patients are travelling abroad or not we can't definitively say," he said, but added that lengthy wait lists are likely at least part of the problem.

Virginia Walley, head of the Ontario Medical Association, also fingered wait times as the reason Ontarians leave for medical procedures. It's the result of government continually underfunding health care, she added.

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News from © The Canadian Press, 2016