By Amanda Boundris
A review by researchers at McMaster University has resulted in new Canadian diabetes screening guidelines, published October 16 in the Canadian Medical Association Journal (CMAJ).
The recommendations were released by the Canadian Task Force on Preventive Health Care (CTFPHC), established by the Public Health Agency of Canada to develop clinical practice guidelines for primary care providers. The Evidence Review and Synthesis Centre (ERSC), based at McMaster, conducts reviews on which the CTFPHC base their guidelines. This systematic review on diabetes screening was led by Diana Sherifali, an assistant professor with the School of Nursing.
The guidelines contain screening recommendations for Type 2 diabetes in adults with no symptoms at low to very high risk of the disease. Chief among them are that routine screening for diabetes in adults of low and moderate risk is not recommended, but it is recommended for those at high and very high risk of developing the condition.
They also suggest using a web-based risk calculator and then based on the predicted risk of diabetes, using the non-fasting A1C blood test to screen. This blood test measures a person's average blood glucose level over the past two to three months, and is easier for patients because they do not need to fast for the test.
The Task Force also recommends:
- Screening every three to five years using the A1C blood test for adults of any age at high risk of diabetes
- For adults at very high risk of diabetes, screen annually using the A1C blood test
- The Finnish Diabetes Risk Score (FINDRISC) or Canadian Diabetes Risk Assessment Questionnaire (CANRISK) are the preferred risk calculators
Risk calculator tools identify patients for screening and may inform patients about their risk factors, such as age, obesity, history of elevated glucose levels, history of hypertension, limited activity levels, and limited fruit and vegetable intake.
"These new guidelines bring precision and convenience with web-based risk calculators and non-fasting A1C to diabetes screening," stated the authors, led by Dr. Kevin Pottie, an associate professor in the University of Ottawa’s Departments of Family Medicine, and Epidemiology and Community Medicine. "Leveraging these tools will help improve health outcomes by empowering patients to take an active role in managing and modifying their own risk factors through interventions like diet and exercise."
For clinicians and patients, the most important thing to take away from the evidence review is that: "It is based on the latest and best available evidence, so there is assurance that the Task Force’s recommendations are evidence-based," said Sherifali.
Diabetes is a chronic disease that has a significant impact on health. It is on the rise in Canada and significant increases are expected over the next decade, according to the Task Force. In 2008-2009, about 2.4 million Canadians – 6.8 per cent of the population – had either Type 1 or Type 2 diabetes, and another 480,000 had diabetes but did not know it.
The full guidelines and evidence review are available for physicians and patients on the Canadian Task Force on Preventive Health Care (CTFPHC) website.