Newcomers to Canada benefit from ‘healthy immigrant effect,’ Toronto study finds

According to the joint study by the Institute for Clinical Evaluative Sciences and U of T, immigrants had a much lower death rate than non-immigrants, even if they happen to live in the most deprived areas in the province.

The mortality rate, or death rate, is a measure of the number of deaths in the population, typically indicated in units of deaths per 1,000 people over a specific time frame.

Immigrants’ lower mortality rate translated into 42,700 fewer deaths overall and 18,400 fewer premature deaths during the study period from 2002 to 2012, the study said.

“We were surprised by the magnitude of the difference. It’s big and substantial,” said U of T epidemiologist Laura Rosella, the lead author of the research paper published in the latest issue of the Journal of Epidemiology & Community Health.

Based on multiple population and demographic databases and the Ontario Registrar General’s death files, as well as census results and immigration records, the study examined the mortality rates across the socioeconomic spectrum among immigrants, native-born Canadians and long-term residents who came here before 1985.

There were 934,765 deaths registered in Ontario during the study period, including 19,501 deaths among female immigrants and 20,514 deaths among male immigrants.

The data showed a higher proportion of immigrants lived in neighbourhoods classified as having in the lowest socioeconomic conditions compared with long-term residents (29.5 per cent vs. 24 per cent for females; and 32.4 per cent vs. 23 per cent for males).

While Rosella said she had expected to see immigrants struggling financially and emotionally would have the highest mortality of all groups, the research showed poverty was instead the overwhelming determinant of health.

“What our study found was despite the healthy immigrant effect, those living in the most deprived areas, irrespective of immigration status, had the highest mortality rates,” said Rosella.

“Immigrants have lower mortality in everywhere we look at. Even when they are in lower socioeconomic status, they are still healthier.”

Rosella attributed the phenomenon partially to what’s known as the “healthy immigrant effect,” which refers to a trend where newcomers to Canada are healthier than the Canadian population, though over time and successive generations, their health as well as that of their children and grandchildren tends to decline.

“The (immigration) system only lets the healthy and resilient ones come,” she explained. “Even when they are in lower status, they have stronger support from their families and communities.”

Although immigrants were found to have a lower mortality rate, their average age at death was approximately six years younger than that of long-term Canadian residents.

Immigrants, mostly chosen by Canada at a prime working age, had a lower age of death because they were among a younger pool of people compared to long-term Canadian residents. For instance, comparing death rates between a high school and a nursing home, the younger population naturally has a lower age of death.

The advantage in mortality among male immigrants over non-immigrants was slightly more pronounced than the gap between female immigrants and non-immigrants, which could be caused by the persistent barriers faced by female immigrants in accessing primary care services in Ontario, said the study.

“These findings support the need to better examine the factors that drive these inequalities to ensure equitable health for the totality of the population,” said Rosella, who is also a scientist at Public Health Ontario.

The research also found long-term residents experienced substantial declines in premature and avoidable mortality over the study period, while declines among immigrants were not as steep over time. Rosella said it is possible that the former may have benefited more from health care and preventative measures.