TORONTO, Ont. – Where you live in the City of Toronto can actually increase your risk of out-of-hospital cardiac arrest by up to five times, according to a new study from St. Michael’s Hospital.

The study determined people living in southwest and central Scarborough, western parts of North York and those in north Etobicoke had the highest rates of out-of-hospital cardiac arrest, at about 500 per 100,000 people.

The lowest rates were found in north Scarborough, downtown Toronto, East York and the northeast part of North York, at about 160 per 100,000 people.

“The risk for cardiac arrest varied widely from one area to another regardless of how close they were to each other on a map,” said Katherine Allan, a PhD student and the lead investigator of the study. “Which means living on the north side of a street that divides two neighbourhoods could mean you’re up to five times more likely to suffer a cardiac arrest.”

Previous studies of hospital cardiac arrests examined where the cardiac arrest took place rather than the victim’s place of residence, according to the study author.

The study traced 5,656 participants, all 20 or older, who had experienced an out-of-hospital cardiac arrest in Toronto from 2006-2010.

The study examined possible factors that are known to contribute to cardiac arrest within each neighbourhood, such as socioeconomic status, education level, income, health status and how activity-friendly the neighbourhoods are.

The study concluded those neighbourhoods with highest household incomes and higher levels of education were all associated with lower risk.

“The data is important for prevention efforts,” Allan said. “We often look at how to prevent cardiac arrest in terms of getting resources to the areas where it occurred, but this research goes back to see what lifestyle factors or behaviours contribute to the risk.”

The study was published in an abstract in the journal Circulation.