Canadians are waiting longer for surgery and other medical treatments than they have in more than 20 years, according to a right-leaning think tank's annual survey of specialist physicians across the country.

The Fraser Institute's new tally of health-care queues found the median wait time for selected medical procedures in Canada rose to 20 weeks this year, up from 18.3 weeks in 2015 and more than double the figure logged in 1993, the year the survey debuted.

"This year is the longest [median] wait that we've ever measured between general practitioner [and] getting treatment. That's quite remarkable," said Bacchus Barua, the think tank's senior economist for health-care studies. "It's a clear indication of the trajectory we've been following over the last 20 or 25 years."

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This latest version of the "Waiting Your Turn" survey comes amid renewed attention to lineups for care in Canada's public health system.

A British Columbia court is currently hearing a constitutional challenge to medicare launched by Brian Day, a doctor and owner of a private surgical centre who argues the province is breaching patients' Charter rights by failing to provide timely medical care.

The provincial, territorial and federal health ministers, meanwhile, are trying to hammer out a health accord to replace a national agreement that expired in 2014 – an agreement that included pan-Canadian targets for wait times for five priority procedures.

Provincial governments are still tracking and making public wait times for those benchmark procedures, including radiation therapy, hip replacements, knee replacements, cataract surgery and cardiac bypass surgery.

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The Canadian Institute for Health Information, an independent agency that publishes health-care statistics, collects provincial figures on wait times for those procedures and a slew of others, but acknowledges there are still differences in how each province gathers its data.

The CIHI's most recent report on wait times, published in March, found that about four out of five Canadians received treatment within the time frame set out by the national benchmarks, which differs for each procedure. Hip replacements, for instance, are supposed to be done in six months. Radiation therapy is supposed to begin within four weeks. The CIHI found that 81 per cent of patients received their hip replacements within that time; the figure was 98 per cent for radiation therapy.

The Fraser Institute's figures are based on a survey that was sent to 11,387 doctors working in 12 different specialties in the first quarter of this year. About one in five responded to the survey, which asked them to estimate total wait times from the initial referral by a general practitioner to the procedure. (The exercise is often criticized because it relies on doctors' recollections of wait times instead of data from patient files or hospital records.)

Based on their responses, the Fraser Institute concluded that Ontario has the shortest median wait times in the country at 15.6 weeks, followed by Saskatchewan (16.6 weeks) and Quebec (18.9 weeks.)

The Maritimes fared worst, with New Brunswick logging the longest median waits (38.8 weeks) followed by Nova Scotia (34.8 weeks), although the report points out that few doctors in the region responded to the survey.

Karen Palmer, a health-policy analyst and adjunct professor at Simon Fraser University in British Columbia, advised against drawing any firm conclusions from the survey. She dismissed it as a "completely wild guess" with too small a sample size and no external peer review.

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"They should just submit this to a journal like the [Canadian Medical Association Journal] and see how it makes it through peer review," she said. "If it does, then it would be worth reading."

But Chris Simpson, a past president of the Canadian Medical Association (CMA), which represents the country's doctors, said the results of the Fraser Institute's past wait-time surveys were often roughly in keeping with the findings of the Wait Time Alliance, which he chaired until that effort quietly folded this year.

The alliance, which was supported by the CMA and associations representing medical specialists, would draw on the provinces' own figures in a bid to report on wait times across the country.

Dr. Simpson, also the vice-dean of medicine at Queen's University in Kingston, said he hopes a new federal-provincial health accord will focus on caring for seniors with chronic health conditions outside hospital, freeing up hospitals to "do what they're supposed to do."

"That will actually be a better solution to permanently fix wait times," he said.