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Where you live in Ontario could determine your risk of heart attack, stroke or dying of cardiovascular disease


Where you live in Ontario has a lot to do with how likely you are to receive preventative healthcare and whether you will suffer a heart attack, stroke or die of cardiovascular disease according to a new study from the Institute for Clinical Evaluative Sciences (ICES) and the Sunnybrook Schulich Heart Centre.

In the study, published today in CMAJ, the researchers looked at 5.5 million adults from 40 to 79 years of age as of January 1, 2008 in Ontario with no previous cardiovascular disease and followed them for five years looking for heart attacks, strokes or cardiovascular-related deaths.

“What we found was a striking variation in the rates of heart attack, stroke or cardiovascular-related death depending on which LHIN a person lived in. There was a clear division between the healthiest and least-healthy LHINs,” says Dr. Jack Tu, the study’s lead author and senior scientist at ICES.

The results of the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) regional variations study, a “big data” initiative, showed cardiovascular event rates had a nearly two-fold variation across Local Health Integration Networks (LHINs) from 3.2 to 5.7 events per 1000 person-years.

The researchers were able to divide Ontario’s 14 LHINs into three distinct groups:

  • Healthiest, (three LHINs) which had the fewest cardiovascular events (3.2-3.5/1000 person-years)
  • Average, (seven LHINs) which had medium event rates  (3.9- 4.7/1000 person-years)
  • Least-healthy, (four LHINs) which had the most cardiovascular events (4.8-5.7/1000 person-years)

People in the three healthiest LHINs, all located in the Greater Toronto Area (Mississauga Halton LHIN, Toronto Central LHIN and Central LHIN ), had the highest average number of family doctor visits, were also more likely to receive an annual physical and be screened for cardiac risk factors such as high cholesterol and diabetes. Blood pressure control in patients with hypertension and statin use (to lower cholesterol levels) among people with diabetes was also higher among those living in the healthiest LHINs. The researchers also found the healthiest LHINs had a relatively high proportion of ethnic minority residents and recent immigrants.

The four least-healthy LHINs were those located in Northern Ontario (North East LHIN and North West LHIN), as well as the North Simcoe Muskoka LHIN and Erie St. Clair LHIN. People in these LHINs were more likely to be obese, smoke and have the lowest dietary intake of fruits and vegetables. People in the highest cardiac event LHINs were also less likely to receive preventative screening tests, have an annual physical and visited a family doctor less frequently.

“Our study shows that the differences in patient and health system factors accounted for nearly 75 per cent of the variation in cardiovascular events between LHINs, suggesting that greater preventative healthcare contributes to lower cardiovascular event rates,” adds Tu, a cardiologist with Sunnybrook Schulich Heart Centre.

The study was funded primarily by an operating grant from the Institute of Circulatory and Respiratory Health-Canadian Institutes of Health Research (ICRH-CIHR).

“Regional variations in ambulatory care and the incidence of cardiovascular events,” was published today in CMAJ.

Additional interactive LHIN-specific population health and health system information is available by visiting the CANHEART eAtlas section on the study website: www.canheart.ca

Author block: Tu JV, Chu A, Maclagan L, Austin PC, Johnston S, Ko DT, Cheung I, Atzema CL, Booth GL, Bhatia RS, Lee DS, Jackevicius CA, Kapral MK, Tu K, Wijeysundera HC, Alter DA, Udell JA, Manuel DG, Mondal P, Hogg W.

The Institute for Clinical Evaluative Sciences (ICES) is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy. For the latest ICES news, follow us on Twitter: @ICESOntario


Deborah Creatura
Media Advisor, ICES
[email protected]
(o) 416-480-4780 or (c) 647-406-5996


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