Income disparities in life expectancy in the City of Toronto and Region of Peel, Ontario.

Introduction: To understand the lack of a gradient in mortality by neighbourhood income in a previous study, we used individual-level data from the 1991-2001 Canadian census mortality follow-up study to examine income-related disparities in life expectancy and probability of survival to age 75 years in the City of Toronto and Region of Peel.

Methods: We calculated period life tables for each sex and income adequacy quintile, overall and separately for immigrants and non-immigrants.

Results: For all cohort members of both sexes, including both immigrants and non-immigrants, there was a clear gradient across the income quintiles, with higher life expectancy in each successively richer quintile. However, the disparities by income were much greater when the analysis was restricted to non-immigrants. The lesser gradient for immigrants appeared to reflect the higher proportion of recent immigrants in the lower income quintiles.

Conclusion: These findings highlight the importance of using individual-level ascertainment of income whenever possible, and of including immigrant status and period of immigration in assessments of health outcomes, especially for areas with a high proportion of immigrants.