Immigration, ethnicity, and avoidable mortality in Canada, 1991-2006

Avoidable mortality is a well-recognized, but less studied indicator of the performance of the health system. First, the study seeks to establish whether immigrants overall and selected foreign-born ethnic groups (Western Europeans, South Asians, Chinese, and Filipinos) have an advantage over nonimmigrants in avoidable mortality. Second, it assesses the effect of sociodemographic and socioeconomic factors on any observed differences by duration of residence.

Deaths grouped by cause of death and by behavioral risk factors, namely smoking-related and alcohol-related, were derived from the 1991 Canadian Census Cohort: Mortality and Cancer Follow-up. The analysis estimated age-standardized mortality rates (ASMRs), rate ratios, and rate differences and also fitted hazard regression models for the overall Canadian-born population and for selected foreign-born ethnicities by sex. Predictors were assessed at baseline.

Compared to the Canadian-born persons, foreign-born men and women had lower ASMRs for overall avoidable mortality and also for selected causes of avoidable mortality. The only exception to this overall trend was for ischemic heart disease among South Asian women. Except for the order of prominence, the three leading causes of death for nonimmigrant and immigrant men and women overall were ischemic heart diseases, smoking-related diseases, and neoplasms. A similar pattern was observed among the ethnic groups, except for circulatory heart diseases replacing ischemic heart diseases and smoking-related diseases among Chinese and Filipino women, respectively. In the hazard regression analysis, the risk of avoidable mortality was lower for immigrants overall and selected ethnicities irrespective of the duration in Canada compared to nonimmigrants. These differences persisted even with adjustment for sociodemographic and socioeconomic factors.

Immigrants overall and the selected ethnicities enjoy an advantage over nonimmigrants in avoidable mortality. However, for certain causes of death especially ischemic heart disease mortality among South Asian women, immigrants appeared worse-off than nonimmigrants. The results suggest differential access to and use of health services, differences in protective health-related behavior, and the healthy immigrant effect.