Table 1 Empirical studies of the health transitions of immigrants to Canada
From: Immigration as pathogenic: a systematic review of the health of immigrants to Canada
| Â | Dataset/Study | Central Research Question | Health measure | Analysis | Results |
|---|---|---|---|---|---|
2010 | |||||
Creatore et al [49] | Ontario Diabetes Database | Is there a relationship between length of time in Ontario and age- and sex-related prevalence of diabetes mellitus? | Diagnosis of diabetes mellitus | Logistic regression | For both men and women, time since immigration displayed a gradient-like pattern with diabetes. Income gradient also detected. |
De Maio and Kemp [20] | LSIC 2001-2005 | To what extent does the health of immigrants deteriorate, and how is this affected by visible minority status and the experience of discrimination? | Self-assessed general health and mental health | Logistic regression | Immigrants' health status deteriorated over the 4-year span of the survey; visible minorities and immigrants that experienced discrimination were most likely to experience worsening health. Some evidence of patterning by socioeconomic status. |
Saposnik et al [50] | PRESARIO | Are recent immigrants to Ontario at a higher risk of premature stroke than long-term residents? | Hospitalization for acute stroke before the age of 65. | Cox proportional hazards model | New immigrants are at a lower risk of premature acute stroke than long-term residents. Controlling for income and the availability of health care services does not explain the pattern. |
Saposnik et al [51] | MARIO | Are recent immigrants to Ontario at a higher risk of myocardial infarction than long-term residents? | Hospitalization for acute myocardial infarction | Cox proportional hazards model | New immigrants are at a lower risk of acute myocardial infarction than long-term residents. Controlling for income and the availability of health care services does not explain the pattern. |
Stafford et al [58] | CCHS 2000/01 | How do rates of psychological distress compare between immigrants and the Canadian-born population? And does this vary by visible minority status and the contextual effect of immigrant density? | Depression via CIDI-SF MD | Multilevel logistic regression | Immigrants were less likely to report depression than the Canadian-born population. As the percentage of immigrants in a region increased, the likelihood of depression for immigrants/visible minorities decreased but it increased for whites. |
Urquia et al [72] | Ontario Discharge Abstract Database | Is there a relationship between length of time in Canada and adverse birth outcomes? | Preterm and small-for-gestational age births | Multilevel logistic regression | A healthy immigrant effect was observed for risk of preterm birth, but not for small-for-gestational birth outcomes. Long-term immigrants at higher risk of preterm birth than the Canadian-born population. |
2009 | |||||
Chiu et al [64] | Survey of homeless immigrants in Toronto in 2004 | Is the healthy immigrant effect generalizable to highly marginalized populations? | Number of chronic conditions, Addiction Severity Index (ASI), and SF-12 health survey | Logistic, Poisson, and linear regression | After adjusting for demographics and lifetime duration of homelessness, recent immigrants hold a health advantage over non-recent immigrants and native-born respondents. |
Lear et al [52] | Multi-Cultural Community Health Assessment Trial | Is time since immigration related to the development of sub-clinical atherosclerosis? | Sub-clinical atherosclerosis | Linear regression | Immigration is associated with an increased risk of sub-clinical atherosclerosis. Over time, immigrants lost an initial advantage and their risk surpassed that of the Canadian-born. |
Moore et al [71] | Québec Birth Registry Data 2000 | Does the association between maternal birthplace, socioeconomic status, and low birth weight vary across immigrant groups and the Canadian-born population? | Low birth weight | Logistic regression | Mixed results, with the strength and direction of the relationship between immigrant status and low birth weight varying by maternal birthplace. Socioeconomic status displayed paradoxical results for some groups, with high SES South Asian- and Caribbean-born mothers having a higher likelihood of low birth weight deliveries than their low SES counterparts. |
Newbold [19] | LSIC 2001-2005 | Is a deterioration of immigrant's health detectable in the short-term? Does this vary by immigrant category (economic, family reunification, and refugee)? | Self-assessed health | Logistic regression and survival analysis | Signs of worsening health among immigrants may be found very quickly (within 2 years). Refugees are most likely to transition to poor health. |
Schaffer et al [62] | CCHS 2002 | Do immigrants differ from the native-born population with respect to bipolar disorder (BD)? And among BD subjects, what factors predict mental health service and 12-month psychotropic medication use? | Self-reported BD (definition based on DSM-IV) and Kessler Psychological Distress Scale (K10). | Direct calculation of BD prevalence | Weighted lifetime prevalence of BD is lower among immigrant, compared to native-born, respondents. Among BD subjects, immigrants were less likely to report use of mental health services and had lower (but not significant) rates of psychotropic medication use. |
Setia et al [55] | NPHS 1994 - 2006 | Does the BMI of immigrants converge with that of the native-born population? | Body mass index | Linear random effects modelling | White male immigrants were the only sub-group to converge to the BMI of the native-born population; other immigrant sub-groups held advantage. |
Veenstra [12] | CCHS 2003 | Does immigrant status explain the health effects of racialization? | Self-reported diagnosis of diabetes and hypertension, self-assessed health status | Logistic regression | Statistically significant differences between White and 'other' racialized groups exist, even after controlling for the healthy immigrant effect. |
2008 | |||||
Auger et al [70] | Extracted from Quebec Birth Registry 1997-2001 | Does a mother's educational attainment interact with immigrant status to influence birth outcomes? | Birth outcomes: small for gestational age, low birth weight, and preterm birth. | Multilevel logistic regression | The influence of immigrant status on birth outcomes differed by educational attainment; immigrant mothers with university education were at higher risk of adverse outcomes. Healthy immigrant effect limited to mothers with low educational attainment. |
Kobayashi et al [40] | CCHS 2000/01 | Does the healthy immigrant effect differ among Canadians of different ethnocultural origins? | Self-assessed health status, Health Utilities Index, activity restriction | Logistic and linear regression | Visible minority immigrants tend to have better health than their Canadian-born counterparts, with the exception of Chinese and South Asian respondents, for whom the Canadian-born have better health. However, the health of foreign-born and Canadian-born respondents converges after controlling for sociodemographic, socioeconomic, and lifestyle variables. |
Stewart et al [67] | Original survey in 10 hospitals (Montreal, Toronto, Vancouver) | Is postpartum depression higher among immigrant women than among Canadian-born women? | Postpartum depression (Edinburgh Postnatal Depression Scale) | Logistic regression | Immigrants, asylum seekers, and refugees were significantly more likely than Canadian-born women to achieve scores reflective of higher risk of postpartum depression. |
2007 | |||||
Leung et al [84] | Original survey of Chinese and white adults in Calgary | Do different measures of health status perform consistently across ethnic populations? | Self-assessed physical and mental health, EQ-5D, number of chronic conditions | Logistic and linear regression | Recent Chinese immigrants were healthier than Canadian-born white population in terms of number of chronic conditions and EQ-5D score. Opposite results when using self-assessed health status and other subjective measures of health. |
Mechakra-Tahiri et al [66] | Québec Longitudinal Study of Child Development | Does postnatal depression vary between immigrants (from minority or majority groups) and Canadians? | Self-assessed health, postnatal depression (CES-D) | Logistic regression | Prevalence of high depressive symptoms were highest among immigrants from minority groups, followed by Canadian-born mothers and finally immigrants from majority groups. |
Ray et al [69] | RIPPLES | Does the healthy immigrant effect apply to the risk of placental disorders? | Maternal placental syndrome (diagnosis of pre-eclampsia or eclampsia, placental abruption or placental infarction) | Logistic regression | Risk of maternal placental syndrome displays a gradient pattern with months since immigration; healthy immigrant effect is present and diminishes over time. |
Smith et al [61] | CCHS 2001/01 | How do rates of depression compare between immigrants and the Canadian-born population? And does the relationship interact with income? | Depression via CIDI-SF MD | Logistic regression | Income may interact with gender and immigrant status as a predictor of depression. Male low-income recent immigrants appear to have lower levels of depression than male mid- to high-income recent immigrants. |
2006 | |||||
Newbold [21] | NPHS 1994/95 - 2000/01 | Does the healthy immigrant effect apply to the presence, number and type of chronic conditions? | Presence (yes/no), number and type of chronic conditions (any, cardiovascular disease, asthma, arthritis, and diabetes) | Logistic regression, proportional hazard modelling | Support for healthy immigrant effect. Arrival cohort also has a significant effect on chronic conditions. Equalization trend in general with immigrants moving toward native-born health status over time. |
Newbold and Filice [33] | CCHS 2000/01 | Does the health of older immigrants (aged 55+) display the healthy immigrant effect? | Self-assessed health, Health Utilities Index, presence, number and type of chronic conditions (heart disease, arthritis, asthma, diabetes, cataracts, cancer, emphysema) | Logistic regression | No differences in health status between Canadian-born and foreign-born Canadians aged 55 and older |
Sword et al [68] | Original survey from 5 hospitals in Ontario | Do patterns of postpartum health differ between immigrant and Canadian-born women? | Self-assessed health, postpartum depression (4 weeks after delivery) | Chi-square analysis | Immigrant women reported lower overall health and were more likely to indicate possible postpartum depression. Time since immigration was not taken into account. |
Zungunegui et al [30] | Health and Social Survey of Quebec 1998, Census of Population and Housing, Police Data | Does community-level unemployment influence the health of immigrants differently than that of the Canadian-born? | Self-assessed health, psychological distress, obesity | Multilevel analysis | At the individual level, no differences between immigrants and non-immigrants in terms of health outcomes. However, in areas of high unemployment immigrants were found to have poorer health in comparison to non-immigrants. |
2005 | |||||
DesMeules et al [73] | Longitudinal Immigration Database, Canadian Mortality Database 1980 - 1998 | Do mortality patterns differ between immigrants, including refugees, and the Canadian-born population? | All-cause and disease-specific mortality rates | Poisson regression | In general, immigrants presented lower all-cause mortality than the Canadian-born population. Some cause-specific mortality rates (stroke, diabetes, AIDS and hepatitis) were higher among some immigrants groups, indicating heterogeneity in the healthy immigrant effect. |
McDonald & Kennedy [53] | NPHS 1996 and CCHS 2001/01 | Is immigration to Canada associated with unhealthy weight gain? | Overweight and obesity | Probit regression | 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. |
Newbold [28] | NPHS 1994/95 - 2000/01 | Do immigrants differ from the native-born population in terms of self-assessed health? Is one group more likely to experience a transition to poor health than the other? | Self-assessed health | Logistic regression, proportional hazard modelling | Mixed support for the health immigrant effect, with immigrants and the native-born equally likely to self-asses their health as poor. Native-born less likely to transition to poor health over time. |
Newbold [97] | NPHS 1994/95 - 2000/01 | How does the health of immigrants to Canada deteriorate over time? | Self-assessed health, presence of chronic conditions | Logistic regression, proportional hazard modelling | Declining health status of recent arrivals regardless of health outcome used in the analysis. Female immigrants and immigrants with low incomes were at greatest risk of transitioning to poor health. |
Ng et al [22] | NPHS 1994/95 - 2002/03 | What factors may contribute to changes in immigrants' health after their arrival in Canada? | Self-assessed health, weight gain, along with health care utilization and health-related activities (smoking, physical activity) | Proportional hazard modeling | Immigrant health converges with the host population. Immigrants most likely to have a decrease in self-assessed health status are of non-European origins. Likelihood of deterioration also related to socio-economic status. |
Wu and Schimmele [57] | NPHS 1996/97 | Does the healthy immigrant effect apply to the risk of depression? | Number of depressive symptoms and experience of major depressive episode | Generalized linear modeling | Depression rates are lower for immigrants than the native-born upon arrival but increases soon after arrival. |
Wu and Schimmele [31] | NPHS 1996/97 | Does immigrant status help to explain racial/ethnic differences in health? | Self-assessed health status, functional health | Linear and cumulative logit regression | No clear pattern between racial/ethnic identity and health inequities. Immigrant status not a significant predictor. |
2004 | |||||
Gee et al [39] | CCHS 2000/01 | Does the healthy immigrant effect apply in mid-age and older-age? | Self-assessed health status, Health Utilities Index, self-reported activity restrictions | Logistic regression | Healthy immigrant effect is present among mid-life (45 - 64 years) immigrants. Immigrants aged 65 and older appear to have worse health than Canadians aged 65 and over, but this disadvantage disappears after controlling for other independent variables. |
Malenfant [76] | Canadian Vital Statistics Data Base | Do rates of suicide differ between immigrants and the Canadian-born population? | Age-standardized suicide rate | Comparison of crude and standardized rates | 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. |
McDonald & Kennedy [29] | NPHS 1996 and CCHS 2000/01 | Does the healthy immigrant effect apply to self-assessed health and the presence of chronic conditions? | Self-assessed health status, presence of chronic conditions | Probit regression | Support for healthy immigrant effect for recent immigrant arrivals. Advantage continues, but to a lesser extent with time since migration. Significant evidence of a cohort effect for immigrant health, though it is insufficient to explain convergence of immigrant health status to the native-born health status. |
Vissandjee et al [43] | CCHS 2000/01 | Does the healthy immigrant effect remain significant after controlling for ethnicity? | Self-assessed health status, presence of chronic conditions | Logistic regression | Female immigrants with less than 2 years in Canada are least likely to self-report poor health, but this advantage may be lost to the point where female immigrants who have been in the country for more than 10 years are the most likely to self-report poor health. |
2003 | |||||
Newbold & Danforth [41] | NPHS 1998/99 | What differences exist in the health of immigrants and the native-born population? Do these differences reflect the effects of social determinants of health? | Self-assessed health status, presence of chronic conditions, Health Utilities Index | Logistic and linear regression | Overall, immigrants were found to have poorer health than non-immigrants. However, the healthy immigrant effect was observed when the period of arrival was controlled for. Those who had been in the country for more than ten years reported worse health than recent immigrants. |
Kobayashi [44] | NPHS 1996/97 | Does immigration status intersect with ethnicity to influence health status in mid- to later-life Canadians? | Presence of chronic conditions | Logistic regression | Significant differences in health status based on time since immigration and country of birth, with recent immigrants from Asia and non-European countries displaying a lower odds of having at least one chronic condition than Canadian-born respondents. |
2002 | |||||
Ali [56] | CCHS 2000/01 | Does the healthy immigrant effect apply to depressive symptoms and alcohol dependence? | Depression and alcohol dependence, both CIDI assessed | Logistic regression | Immigrants were found to have lower rates of depression and alcohol dependence than the Canadian-born population. This advantage diminishes as length of residence in Canada increases. |
Beiser et al [63] | NLSCY 1994/95 | Does the healthy immigrant effect apply to the mental health of immigrant children? | Psychometric scales of emotional and behavioural problems | Linear regression | Foreign-born children had lower levels of emotional and behavioural problems than Canadian-born children, despite being twice as likely to live in poor families. |
Pérez [45] | CCHS 2000/01 | Does the healthy immigrant effect apply to chronic conditions? | Presence of chronic conditions | Logistic regression | Both male and female immigrants had lower odds of reporting chronic conditions than the Canadian-born respondents, and these odds increased with time since immigration. Male immigrants had lower rates of heart disease than native born males. Women immigrants had lower rates of cancer than the Canadian-born respondents. With respect to diabetes and high blood pressure, no differences were observed. |
Payne et al [74] | Canadian Mortality Database 1980-1998 | What factors may be associated with mortality for immigrant women? | Standardized mortality ratios | Poisson regression | Significantly increased risk of mortality among certain groups of women, including among refugees versus non-refugees. |
2001 | |||||
Kopec et al [36] | NPHS 1994/95 | What differences exist in health status between cultural groups defined by place of birth and language? | Health Utilities Index | Logistic regression | Mixed support for the health immigrant effect, with some (but not all) immigrant groups reporting higher levels of health than Canadian-born respondents. |
2000 | |||||
Dunn & Dyck [46] | NPHS 1994/95 | Do social determinants of health influence the health of immigrants and the Canadian-born population in different ways? | Self-assessed health status, presence of a chronic condition | Logistic regression | Ambiguous results with no consistent patterns between socio-economic characteristics and health status or immigration characteristics and health status. Socio-economic factors may be more important for immigrants than non-immigrants. |
Laroche [10] | GSS 1985, 1991 | Does the health status of immigrants differ from that of the Canadian-born population? | Self-assessed health status, long-term activity limitation | Probit regression | Health status of immigrants does not differ significantly from that of the Canadian-born population. However, immigrants are less likely to report long-term activity limitation than the native-born. |
Wang et al [47] | NPHS 1994 | Do arthritis rates differ between immigrants from Asia, Europe/Australia, and the Canadian-born population? | Arthritis or rheumatism | Logistic regression | Age-sex adjusted rates of arthritis were lowest for immigrants from Asia, followed by immigrants from Europe/Australia and finally, Canadian-born respondents. |
1999 and earlier | |||||
Cairney & Ostbye [54] | NPHS 1994 | Is time since immigration associated with excess body weight? | Self-reported height and weight | Logistic and linear regression | Prevalence of excess weight increases after immigration for both men and women. Adjusted models indicate the healthy immigrant effect may apply to women and Asian men. |
Chen et al [48] | NPHS 1994/95 | Do immigrants differ from the Canadian-born population with respect to asthma? | Asthma | Logistic regression | Immigrant status and household income were significant predictors of asthma prevalence for both men and women. |
Chen, Wilkins, & Ng [75] | Canadian Vital Statistics Data Base 1985-87, 1990-92, Census 1986, 1991, Health and Activity Limitation Survey 1986-87, 1991 | Does life expectancy vary between immigrants and the Canadian-born population? | Crude, disability- and dependency-adjusted life expectancy | Prevalence estimates | Support for the healthy immigrant effect. Immigrants, particularly those from a non-European country, had a longer life expectancy and more years free of disability and dependency |
Chen, Ng, & Wilkins [42] | NPHS 1994/95 | Does the healthy immigrant effect apply in Canada? | Presence of a chronic condition, disability, and health-related dependency | Prevalence estimates | Non-European immigrants in particular and immigrants in general were healthier than non-immigrants for chronic conditions. Prevalence of chronic conditions increases with time since immigration. |
Noh and Avison [65] | Korean Mental Health Study 1990-91 | How are stressors and psychological/social resources related to psychological distress among Korean immigrants? | Psychological distress based on CES-D (translated) | Linear regression | Number of years in Canada does not appear to influence levels of psychological distress. |
Parakuluam et al [98] | GSS 1985, Census 1981 | Does the health status of the Canadian-born differ from that of foreign-born residents? | Derived 'healthfulness' index (presence of chronic conditions, utilization of health services, activity limitation or disability) | Descriptive statistics | Overall, immigrants are healthier than native-born Canadians. |