Cancer incidence among Canadian immigrants, 1980-1998: results from a national cohort study.

Canadian immigrants have lower overall cancer risk than the Canadian-born population. Less is known about risks for immigrant subgroups and site-specific cancers. Linked administrative data sets were used to compare cancer incidence between subgroups of immigrants to Canada and the general Canadian population. The study involved 128,962 refugees and 241,010 non-refugees. Standardized incidence ratios (SIRs) were calculated for all-site and site-specific cancers by immigration categories and regions of birth. Relative to the general Canadian population, incidence of all-site cancer was lower among immigrants overall, by sex and refugee status (non-refugee SIRs 0.25: men, 0.24: women; refugee SIRs 0.31: both). Significantly higher SIRs resulted for liver, nasopharyngeal and cervical cancers, including liver cancer among South-East Asian and North-East Asian immigrants, and nasopharyngeal cancer among North-East Asian non-refugees. Hypothesized explanations for variation in cancer incidence include earlier viral infection in the country of origin.

Disparities in mortality patterns among Canadian immigrants and refugees, 1980-1998: results of a national cohort study.

This study examines mortality patterns among Canadian immigrants, including both refugees and non-refugees, 1980-1998. Records of a stratified random sample of Canadian immigrants landing between 1980-1990 (N = 369,936) were probabilistically linked to mortality data (1980-1998). Mortality rates among immigrants were compared to those of the general Canadian population, stratifying by age, sex, immigration category, region of birth and time in Canada. Multivariate analysis examined mortality risks for various immigrant subgroups. Although immigrants presented lower all-cause mortality than the general Canadian population (SMR between 0.34 and 0.58), some cause-specific mortality rates were elevated among immigrants, including mortality from stroke, diabetes, infectious diseases (AIDS and hepatitis among certain subgroups), and certain cancers (liver and nasopharynx). Mortality rates differed by region of birth, and were higher among refugees than other immigrants. These results support the need to consider the heterogeneity of immigrant populations and vulnerable subgroups when developing targeted interventions.

New approaches to immigrant health assessment.

While immigrant subgroups may present vulnerabilities in terms of health status, health service use, and social determinants, comprehensive information on their health is lacking. To examine mortality (1980-1998) and health service utilization (1985-2002) patterns in Canadian immigrants, a record linkage pan-Canadian research initiative using immigration and health databases has been undertaken. Preliminary results indicate that overall mortality is low among Canadian immigrants as compared to the general population for most leading causes (thus supporting the notion of "healthy immigrant effect"), with cause-specific exceptions. Moreover, results from British Columbia show that overall physician visits are low for immigrants, but not for all subgroups. Results from Ontario demonstrate a sharp increase in physician claims approximately three months following landing. Future analyses will address the short- and long-term health outcomes of immigrant subgroups, including less common diseases. Results are pertinent to practitioners working with immigrants and can inform immigrant health policy.