The chair of the committee that devised the new recommendations says he hopes the document will clear up the confusion that exists among family doctors around the issue of diabetes screening.
Dr. Kevin Pottie says the new Canadian Task Force on Preventive Health Care guidelines advises doctors not to screen adults routinely unless they are at high or very high risk of developing Type 2 diabetes.
People at high risk of developing the disease should undergo a blood test every three to five years, and those at very high risk should be screened annually.
The panel says low and moderate risk adults aged 18 and older should not be tested, because there is no evidence that it would be of any benefit to them.
The recommendations suggest doctors use one of two approved risk calculation tools to slot patients into their risk category.
And the guidelines suggest individuals themselves should keep an eye on their personal risk over time.
The guidelines were published online Tuesday by the Canadian Medical Association Journal.
This new guidance could lead to a major shift in practice for some doctors, who may be ordering fasting glucose blood tests as a routine part of an annual physical examination, at least for middle-aged or overweight patients.
"I think that there's been a real lack of precision around diabetes approaches. And I think we really worked hard to try to use the evidence to become more precise," says Pottie, who chaired the task force's diabetes working group.
"I think what we're doing is we're saying: Well, really, the evidence is quite clear that for low and moderate risk people, there is no evidence of any benefit from doing that blood test."
Pottie is an associate professor of family medicine, epidemiology and community medicine at the University of Ottawa.
Diabetes is a large and growing problem in Canada, with an estimated 2.4 million Canadians suffering from either Type 1 (early onset) or Type 2 diabetes. It's also estimated that nearly a half-million more Canadians have diabetes but don't know it.
Uncontrolled diabetes can lead to long-term health consequences, including increased risk of cardiovascular disease, blindness and risk of foot wounds that could led to amputation.
The new guidelines aren't suggesting doctors take the condition less seriously. In fact, in urging doctors to slot patients into risk categories, the panel is suggesting doctors and patients evaluate the risk on an ongoing basis.
But the guidance does say doctors should not order blood tests for people who aren't likely to have the condition.
The guidance also says that when people are screened for diabetes, a newer blood test that measures something called A1C should be used instead of the traditional fasting glucose test.
That cumbersome test required people to go at least eight hours without eating before having their blood drawn.
This marks the first time since 2005 that the task force has issued guidance to doctors on diabetes screening. The task force was disbanded in 2005 and only reformed in 2010.
The old guidelines told doctors to test patients who had high blood pressure or high cholesterol, because both conditions put people at risk of developing Type 2 diabetes.
In 2008, the Canadian Diabetes Association advised doctors to screen patients 40 and older for diabetes, though its recommendation was vague about how frequently screening should be conducted.
The new guidelines were drawn up after the working group reviewed and graded the accumulated medical literature on diabetes screening. Pottie admits the new recommendations may be met with some pushback.
"To be honest, I would suggest there may be some resistance because we are actually going to be asking physicians to do risk calculations (on patients)," he says.
The panel recommended two validated calculation tools, a European one known as FINDRISC or a newer Canadian tool called CANRISK that is found on the Public Health Agency of Canada's website.
They assess a person's personal risk by considering factors like one's family history of diabetes, body mass index, diet and exercise patterns and age.
On the web:
The Canadian Task Force on Preventive Health Care's diabetes recommendations, http://bit.ly/V6ME5r
The CANRISK diabetes calculation tool, http://bit.ly/V52tE7