Table 2 Overview of results by outcome measure
From: Immigration as pathogenic: a systematic review of the health of immigrants to Canada
| Â | Number of studies | Results/Emerging Themes |
|---|---|---|
Self-assessed health status | Â | Â |
- Likert scale | 18 | Using social surveys such as the NPHS, the CCHS, and the LSIC, these studies have shown (with a few exceptions) that the health of immigrants is better than that of the Canadian-born population at time of arrival and that this advantage is lost over time. |
- Health Utilities Index (HUI) | 5 | Studies using the HUI detected the healthy immigrant effect among mid-life (aged 45-64 years of age) immigrants and among visible minorities. Results from HUI studies also emphasize the heterogeneity found among immigrants, with significant differences in the reporting of pain, emotional function, and cognitive function among different immigrant groups. |
Chronic conditions | Â | Â |
- Presence of chronic conditions | 14 | Overall support for the healthy immigrant effect, with some exceptions - likely attributable to conflation of different kinds of conditions into a dichotomous outcome (1 = yes, 0 = no). |
- Arthritis | 1 | Age-sex adjusted rates of arthritis are lower among immigrants than the Canadian-born population. Effect of duration of residence is unknown. |
- Asthma | 1 | Prevalence of asthma is lower among immigrants than the Canadian-born population. Effect of duration of residence is unknown. |
- Cardiovascular diseases | 3 | Immigrants enjoy lower risks of premature acute stroke and myocardial infarction, even after adjusting for income and availability of health care services. Duration of residence is associated with sub-clinical atherosclerosis. |
- Diabetes | 5 | Mixed results. Some indication that immigrants enjoy lower rates of diabetes, even after adjusting for income, educational attainment, age, and other factors. However, new data shows that recent immigrants, particularly women and immigrants of South Asian and African origin, may be at a higher risk for diabetes mellitus compared to long-term residents. |
Obesity | 5 | On average, immigrants are less likely to be obese or overweight than the Canadian-born population at the time of their arrival. This advantage is lost over time - but this varies by the ethnicity of the immigrant. Most recent findings suggest that white male immigrants are most likely to converge to Canadian-born rates of obesity; other immigrant groups tend to enjoy lower BMI even over time. |
Mental health | Â | Â |
- Depression/distress/other | 10 | Depression and other mental health issues may be less prevalent among immigrants than the Canadian-born population. However, this advantage diminishes as length of residence in Canada increases. Living in areas with a high density of immigrants may help immigrants to retain this advantage. Immigrants who experience discrimination may be more likely to report worsening health. Income may interact with gender as a determinant of mental health, with mid-/high-income immigrants faring worse than expected given their income status. |
- Postpartum depression | 3 | Postpartum depression may be more prevalent among immigrant women than Canadian-born women. However, studies in this area have not controlled for time in Canada; differences between recent- and long-term immigrants may be confounded in the results. |
Birth outcomes | 4 | Time in Canada may be associated with an increased risk of placental disorder and preterm birth but not for small for gestational age births. Highly educated immigrant women experience worse than expected outcomes. |
Mortality | 3 | Some indication of lower mortality risk among immigrants overall, but with considerable heterogeneity in patterns by cause and between type of immigrant (economic, family, refugee) |
Suicide | 1 | Suicide rates for the immigrant population is about half that of the Canadian population. Increases in age are associated with increases in suicide among immigrants, whereas the opposite holds for the Canadian-born. |