Remigration of migrants with severe disease: myth or reality?--a register-based cohort study

Adding ethnicity to cardiovascular risk prediction: External validation and model updating of SCORE2 using data from the HELIUS population cohort

BACKGROUND

Current prediction models for mainland Europe do not include ethnicity, despite ethnic disparities in cardiovascular disease (CVD) risk. SCORE2 performance was evaluated across the largest ethnic groups in the Netherlands and ethnic backgrounds were added to the model.

METHODS

11,614 participants, aged between 40 and 70 years without CVD, from the population-based multi-ethnic HELIUS study were included. Fine and Gray models were used to calculate sub-distribution hazard ratios (SHR) for South-Asian Surinamese, African Surinamese, Ghanaian, Turkish and Moroccan origin groups, representing their CVD risk relative to the Dutch group, on top of individual SCORE2 risk predictions. Model performance was evaluated by discrimination, calibration and net reclassification index (NRI).

RESULTS

Overall, 274 fatal and non-fatal CVD events, and 146 non-cardiovascular deaths were observed during a median of 7.8 years follow-up (IQR 6.8-8.8). SHRs for CVD events were 1.86 (95 % CI 1.31-2.65) for the South-Asian Surinamese, 1.09 (95 % CI 0.76-1.56) for the African-Surinamese, 1.48 (95 % CI 0.94-2.31) for the Ghanaian, 1.63 (95 % CI 1.09-2.44) for the Turkish, and 0.67 (95 % CI 0.39-1.18) for the Moroccan origin groups. Adding ethnicity to SCORE2 yielded comparable calibration and discrimination [0.764 (95 % CI 0.735-0.792) vs. 0.769 (95 % CI 0.740-0.797)]. The NRI for adding ethnicity to SCORE2 was 0.24 (95 % CI 0.18-0.31) for events and - 0.12 (95 % CI -0.13-0.12) for non-events.

CONCLUSIONS

Adding ethnicity to the SCORE2 risk prediction model in a middle-aged, multi-ethnic Dutch population did not improve overall discrimination but improved risk classification, potentially helping to address CVD disparities through timely treatment.

Cancer mortality by country of birth and cancer type in Sweden: A 25-year registry-based cohort study

Numerous studies have reported lower overall cancer mortality rates among immigrants compared to native populations. However, limited information exists regarding cancer mortality among immigrants based on specific birth countries and cancer types. We used population-based registries and followed 10 million individuals aged 20 years or older in Sweden between 1992 and 2016. The Cox proportional hazard model was used to explore the disparities in cancer mortality by country of birth and cancer type, stratified by gender. Age-standardized mortality rates were also computed using the world standard population. Hazard ratio (HR) of all-site cancer was slightly lower among immigrants (males: HRm = 0.97: 95% confidence interval: 0.95, 0.98; females: HRf = 0.93: 0.91, 0.94) than Swedish-born population. However, the immigrants showed higher mortality for infection-related cancers, including liver (HRf = 1.10: 1.01, 1.19; HRm = 1.10: 1.02, 1.17), stomach (HRf = 1.39: 1.31, 1.49; HRm = 1.33: 1.26, 1.41) cancers, and tobacco-related cancers, including lung (HRm = 1.44: 1.40, 1.49), and laryngeal cancers (HRm = 1.47: 1.24, 1.75). The HR of mesothelioma was also significantly higher in immigrants (HRf = 1.44: 1.10, 1.90). Mortality from lung cancer was specifically higher in men from Nordic (HRm = 1.41: 1.27, 1.55) and non-Nordic Europe (HRm = 1.49: 1.43, 1.55) countries and lower in Asian (HRm = 0.78: 0.66, 0.93) and South American men (HRm = 0.70: 0.57, 0.87). In conclusion, there are large variations in cancer mortality by country of birth, and cancer type and require regular surveillance. Our detailed analyses lead to some novel findings such as excess mortality rate of mesothelioma and laryngeal cancers in Immigrants in Sweden. A targeted cancer prevention program among immigrants in Sweden is needed.

Advancing migration and health research by examining return migration

This essay offers an analysis of research on return migration and health by adopting the social determinants of health (SDH) framework proposed by the WHO. Specifically, we argue that the SDH are implicated in the decision to migrate, stay or return, which in itself also contributes to social health inequities. Most theoretical frameworks developed to study migration have predominantly considered primary migration movements. The lack of a fluid consideration of the migration phenomenon has a direct impact on our understanding of the relationship between migration and health. In this essay, we, first, address the challenges of defining and studying return and its implications for health research. Second, we propose to use the WHO's SDH framework to understand how social factors shape migrants' health, influence the decision to return and can contribute to health inequalities. The conceptual approach developed in this paper can help design future studies on the health of return migrants, fostering interdisciplinary collaborations to investigate how social factors are embodied, giving rise to health inequities in society that are intricately linked to the migration experience.

Differences in the risk of premature cancer mortality between natives and immigrants in Spain

BACKGROUND

The healthy immigrant paradox has found wide support in the literature. To evaluate this hypothesis that immigrants have better health outcomes than the native population, this study aimed to compare the premature cancer mortality between the native and immigrant populations in Spain.

METHODS

We obtained the 2012-15 cause-specific mortality estimates from administrative records and participant characteristics data from the 2011 Spanish census. Using Cox proportional hazards regression models, we calculated the risks of mortality of the native and immigrant populations, and the latter populations' risk based on their regions of origin, and determined the effects of covariates of interest on the calculated risk.

RESULTS

Our results show that the risk of premature cancer mortality is lower among immigrants than among natives, and this gap is higher among men than among women. There is a lower mortality rate among Latin American immigrants (Latino men are 81% less likely to die prematurely from cancer than native-born men, and Latino women are 54% less). Moreover, despite social class disparities, immigrants' advantage in cancer mortality remained constant and decreased with increasing length of residence in the host country.

CONCLUSIONS

This study provided novel evidence on the 'healthy immigrant paradox', associated with the fact that migrants are favorably selected at origin, cultural patterns of the societies of origin and, in the case of men, there is some convergence or an 'unhealthy' integration that explains the fact that this advantage over natives is lost with more years of residence in Spain.

Are migrants diagnosed with a trauma-related disorder at risk of premature mortality? A register-based cohort study in Denmark

Background

Mental illness is common among refugees displaced by conflict and war. While evidence points to the relatively good health in terms of longevity of migrants resettled in the destination country, less is known about the mortality of the most vulnerable migrants with a trauma-related diagnosis alone and those with an additional comorbid psychotic disorder. This study aimed to provide an overview of the number and mortality of foreign-born individuals diagnosed with Post-Traumatic Stress Disorder or Enduring Personality Change after a Catastrophic Event (PTSD/EPCACE), a psychotic disorder or both.

Methods

A nationwide register-based cohort study, including residents in Denmark, followed from 1 January 1995 to 31 December 2016. The exposure was PTSD/EPCACE and psychotic disorders as well as region of origin. Relative all-cause mortality was estimated using Cox proportional hazards regression models and calculated for migrants with one or both groups of disorders compared to those from the same region without the disorder.

Results

During the study period, 6,580,000 individuals (50.4% women) were included in the cohort. Of these 1,249,654 (50.5% women) died during follow-up. For men and women from the former Yugoslavia, the Middle East and Northern Africa, a PTSD/EPCACE diagnosis alone or with comorbid psychotic disorder was not associated with increased mortality after adjusting for region of origin. A psychotic disorder alone, however, was associated with an increased mortality rate.

Conclusion

Despite the severity of many refugees' traumatic experiences, a diagnosis of a trauma-related psychiatric disorder did not appear to increase the mortality rates.

Mortality Advantage Reversed: The Causes of Death Driving All-Cause Mortality Differentials Between Immigrants, the Descendants of Immigrants and Ancestral Natives in Sweden, 1997-2016

A small but growing body of studies have documented the alarming mortality situation of adult descendants of migrants in a number of European countries. Nearly all of them have focused on all-cause mortality to reveal these important health inequalities. This paper takes advantage of the Swedish population registers to study all-cause and cause-specific mortality among men and women aged 15-44 in Sweden from 1997 to 2016 to a level of granularity unparalleled elsewhere. It adopts a multi-generation, multi-origin and multi-cause-of-death approach. Using extended, competing-risks survival models, it aims to show (1) how the all-cause mortality of immigrants arriving as adults (the G1), immigrants arriving as children (the G1.5) and children of immigrants born in Sweden to at least one immigrant parent (the G2) differs versus ancestral Swedes and (2) what causes-of-deaths drive these differentials. For all-cause mortality, most G1 (not Finns or Sub-Saharan Africans) have a mortality advantage. This contrasts with a near systematic reversal in the mortality of the G1.5 and G2 (notably among men), which is driven by excess accident and injury, suicide, substance use and other external cause mortality. Given that external causes-of-death are preventable and avoidable, the findings raise questions about integration processes, the levels of inequality immigrant populations are exposed to in Sweden and ultimately, whether the legacy of immigration has been positive. Strengths of the study include the use of quality data and advanced methods, the granularity of the estimates, and the provision of evidence that highlights the precarious mortality situation of the seldom-studied G1.5.

Immigration, mortality, and national life expectancy in the Nordic region, 1990–2019

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Immigrants have higher life expectancy at age 1 than the native-born in Denmark, Finland and Norway do from 1990 to 2019.

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Immigrants in Denmark, Finland and Norway increasingly enhance national life expectancy at age 1 over time.

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Immigrants in Sweden have lower life expectancy at age 1 than native-born in Sweden do in 1990, but similar levels by 2019.

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The effect of immigrants on national life expectancy at age 1 in Sweden transforms from negative to positive over time.

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The unique mortality of immigrants affects rankings of life expectancy at age 1 in the Nordic region in recent years.

Investigating the salmon bias effect among international immigrants in Sweden: a register-based open cohort study

Background

Studies of migration and health have hypothesized that immigrants may emigrate when they develop poor health (salmon bias effect), which may partially explain the mortality advantage observed among immigrants in high-income countries. We evaluated the salmon bias effect by comparing the health of immigrants in Sweden who emigrated with those who remained, while also exploring potential variation by macro-economic conditions, duration of residence and region of origin.

Methods

A longitudinal, open cohort study design was used to assess risk of emigration between 1992 and 2016 among all adult (18+ years) foreign-born persons who immigrated to Sweden between 1965 and 2012 (n = 1 765 459). The Charlson Comorbidity Index was used to measure health status, using information on hospitalizations from the Swedish National Patient Register. Poisson regression models were used to estimate incidence rate ratios (RRs) with 95% confidence intervals (CIs) for emigrating from Sweden.

Results

Immigrants with low (RR = 0.83; 95% CI: 0.76–0.90) moderate (RR = 0.70; 95% CI: 0.62–0.80) and high (RR = 0.62; 95% CI: 0.48–0.82) levels of comorbidities had decreased risk of emigration relative to those with no comorbidities. There was no evidence of variation by health status in emigration during periods of economic recession or by duration of residence. Individuals with low to moderate levels of comorbidities from some regions of origin had an increased risk of emigration relative to those with no comorbidities.

Conclusions

The study results do not support the existence of a salmon bias effect as a universal phenomenon among international immigrants in Sweden.

Mortality differences between migrants and Italians residing in Rome before, during, and in the aftermath of the great recession. A longitudinal cohort study from 2001 to 2015

Background

In Europe, one of the most consistent findings is that of migrant mortality advantage in high-income countries. Furthermore, the literature shows that economic shocks, which bring worse health outcomes, can severely affect the most disadvantaged individuals. We analyse differences and changes in all-cause mortality between Italians and migrants residing in Rome before, during, and in the aftermath of the Great Recession (2001–2015) by birth-cohort.

Methods

The analysis is a longitudinal open cohort study. Mortality data come from the Register of the Causes of Death (58,637 deaths) and the population denominator (n = 2,454,410) comes from the Municipal Register of Rome. By comparing three time-periods (2001–2005, 2006–2010, and 2011–2015), we analyse all-cause mortality of Rome residents born, respectively, in the intervals 1937–1976, 1942–1981, 1947–1986 (aged 25–64 years at entry into observation). Computing birth-cohort-specific death rates and applying parametric survival models with age as the time-scale, we compare mortality differences between migrants and Italians by gender, area of origin, and time-period.

Results

Overall, we find a lower risk of dying for migrants than Italians regardless of gender (Women: HR = 0.61, 95% CI 0.56–0.66; Men: HR = 0.49, 95% CI 0.45–0.53), and a lower death risk over time for the total population. Nevertheless, such a pattern changes according to gender and migrants’ area of origin.

Conclusion

Given the relevance of international migrations in Europe, studying migrants’ health has proved increasingly important. The deterioration in migrant health and the gradual weakening of migrants’ mortality advantage is likely to become a public health issue with important consequences for the healthcare system of all European countries.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12176-8.

Importance of accounting for loss to follow-up when comparing mortality between immigrants and long-term residents: a population-based retrospective cohort

OBJECTIVES

To evaluate the association between immigration status and all-cause mortality in different disease cohorts, and the impact of loss to follow-up on the observed associations.

DESIGN

Population-based retrospective cohort study using linked administrative health data in Ontario, Canada.

SETTING

We followed adults with a first-ever diagnosis of ischaemic stroke, cancer or schizophrenia between 2002 and 2013 from index event to death, loss to follow-up, or end of follow-up in 2018.

PRIMARY AND SECONDARY OUTCOME MEASURES

Our outcomes of interest were all-cause mortality and loss to follow-up. For each disease cohort, we calculated adjusted HRs of death in immigrants compared with long-term residents, adjusting for demographic characteristics and comorbidities, with and without censoring for those who were lost to follow-up. We calculated the ratio of two the HRs and the respective CL using bootstrapping methods.

RESULTS

Immigrants were more likely to be lost to follow-up than long-term residents in all disease cohorts. Not accounting for this loss to follow-up overestimated the magnitude of the association between immigration status and mortality in those with ischaemic stroke (HR of death before vs after accounting for censoring: 0.78 vs 0.83, ratio=0.95; 95% CL 0.93 to 0.97), cancer (0.74 vs 0.78, ratio=0.96; 0.95 to 0.96), and schizophrenia (0.54 vs 0.56, ratio=0.97; 0.96 to 0.98).

CONCLUSIONS

Immigrants to Canada have a survival advantage that varies by the disease studied. The magnitude of this advantage is modestly overestimated by not accounting for the higher loss to follow-up in immigrants.

Factors Associated with Return Migration of First-Generation Immigrants in Belgium (2001-2011)

Belgium is a country with a long and diverse history of migration. Given the diverse context of immigration to Belgium, reasons for return migration will most likely vary as well. With this study, we want to quantify the return migration of Belgium's immigrants and assess whether socio-economic, sociodemographic and health factors are related to return migration. Individually linked census and register data comprising the total Belgian first-generation immigrant population aged 25+ were used. Age-standardized emigration rates (ASER) by migrant origin and gender were calculated for the period 2001-2011. Additionally, relative return migration differences were calculated by country of origin and gender, adjusted for age group, length of stay, household composition, socio-economic indicators (education, home ownership and employment status) and self-rated health in 2001. Return migration was most common among immigrants from Spanish descent and from the neighbouring countries and higher among men than among women. Return migration was highly selective in terms of older age, lower length of stay in Belgium, not living with a partner or children, being high-educated, unemployed and in good health. Key issues for future research include examining the reasons for return migration, identifying the country of destination and accounting for household characteristics.

Amyotrophic lateral sclerosis (ALS) among immigrant groups and Swedish-born individuals: a cohort study of all adults 18 years of age and older in Sweden

Background

There is a lack of studies of amyotrophic lateral sclerosis (ALS) in immigrants.

Objective

The objective is to study the association between country of birth and incident ALS in first-generation immigrants versus Swedish-born individuals, and in second-generation immigrants versus native Swedes.

Methods

Study populations included all adults aged 18 years and older in Sweden, in the first-generation study 6,128,698 individuals (2,975,141 men, 3,153,557 women) with 5,344 ALS cases (3017 men, 2327 women), and in the second-generation study 4,588,845 individuals (2,346,855 men and 2,241,990 women) with 3,420 cases (2027 men and 1393 women). ALS was defined as having at least one registered diagnosis of ALS in the National Patient Register 1998–2017. The incidence of ALS in different first-generation immigrant groups versus Swedish-born individuals was assessed by Cox regression, expressed as hazard ratios (HRs) with 95% confidence intervals (CI). The models were stratified by sex and adjusted for age, geographical residence in Sweden, educational level, marital status, and neighbourhood socioeconomic status.

Results

After adjusting for potential confounders, the HRs were lower in foreign-born men, 0.71 (95% CI 0.63–0.81), and women, 0.80 (95% CI 0.70–0.92). The ALS risk was lower among men and women from most Western countries (Europe outside Nordic countries, and North America), and from other regions of the world (Africa, Asia, and Latin America). Among men and women with foreign-born parents, the risk of ALS did not differ significantly from native Swedes.

Significance

In general, the risk of ALS was lower in first-generation men and women but did not differ in second-generation individuals.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10765-6.

Risk factors, awareness of disease and use of medications in a deprived population: differences between indigent natives and undocumented migrants in Italy

BACKGROUND

Undocumented migrants experience many health problems; a comparison with a suitable control group of natives living in the same socio-economic conditions is still lacking.

METHODS

Demographic data and data on risk factors, chronic conditions and dietary habits were obtained for 6933 adults (2950 Italians and 3983 undocumented migrants) receiving medical assistance from 40 non-governmental organizations all over the country.

RESULTS

Attributed to the fact that these were unselected groups, differences were found in their demographic features, the main ones being their marital status (singles: 50.5% among Italians and 42.8% among migrants; P < 0.001). Smokers were more frequent among Italians (45.3% versus 42.7% P = 0.03); the same happened with hypertension (40.5% versus 34.5% P < 0.001). Migrants were more often overweight (44.1% versus 40.5% P < 0.001) and reporting a chronic condition (20.2% versus 14.4% P < 0.001). Among those on medications (n = 1354), Italians were fewer (n = 425) and on different medications. Differences emerged also in dietary habits.

CONCLUSIONS

Differences in health conditions exist between native-borns and undocumented migrants, not because of a bias related to socio-economic conditions. Further studies are needed to design sustainable health policies and tailored prevention plans.

Mortality in first- and second-generation immigrants to Sweden diagnosed with type 2 diabetes: a 10 year nationwide cohort study

AIMS/HYPOTHESIS

Non-Western immigrants to Europe are at high risk for type 2 diabetes. In this nationwide study including incident cases of type 2 diabetes, the aim was to compare all-cause mortality (ACM) and cause-specific mortality (CSM) rates in first- and second-generation immigrants with native Swedes.

METHODS

People living in Sweden diagnosed with new-onset pharmacologically treated type 2 diabetes between 2006 and 2012 were identified through the Swedish Prescribed Drug Register. They were followed until 31 December 2016 for ACM and until 31 December 2012 for CSM. Analyses were adjusted for age at diagnosis, sex, socioeconomic status, education, treatment and region. Associations were assessed using Cox regression analysis.

RESULTS

In total, 138,085 individuals were diagnosed with type 2 diabetes between 2006 and 2012 and fulfilled inclusion criteria. Of these, 102,163 (74.0%) were native Swedes, 28,819 (20.9%) were first-generation immigrants and 7103 (5.1%) were second-generation immigrants with either one or both parents born outside Sweden. First-generation immigrants had lower ACM rate (HR 0.80 [95% CI 0.76, 0.84]) compared with native Swedes. The mortality rates were particularly low in people born in non-Western regions (0.46 [0.42, 0.50]; the Middle East, 0.41 [0.36, 0.47]; Asia, 0.53 [0.43, 0.66]; Africa, 0.47 [0.38, 0.59]; and Latin America, 0.53 [0.42, 0.68]). ACM rates decreased with older age at migration and shorter stay in Sweden. Compared with native Swedes, first-generation immigrants with ≤ 24 years in Sweden (0.55 [0.51, 0.60]) displayed lower ACM rates than those spending >24 years in Sweden (0.92 [0.87, 0.97]). Second-generation immigrants did not have better survival rates than native Swedes but rather displayed higher ACM rates for people with both parents born abroad (1.28 [1.05, 1.56]).

CONCLUSIONS/INTERPRETATION

In people with type 2 diabetes, the lower mortality rate in first-generation non-Western immigrants compared with native Swedes was reduced over time and was equalised in second-generation immigrants. These findings suggest that acculturation to Western culture may impact ACM and CSM in immigrants with type 2 diabetes but further investigation is needed. Graphical abstract.

Country of birth and mortality risk in hypertension with and without diabetes: the Swedish primary care cardiovascular database

OBJECTIVES

Hypertension and diabetes are common and are both associated with high cardiovascular morbidity and mortality. We aimed to investigate associations between mortality risk and country of birth among hypertensive individuals in primary care with and without concomitant diabetes, which has not been studied previously. In addition, we aimed to study the corresponding risks of myocardial infarction and ischemic stroke.

METHODS

This observational cohort study of 62 557 individuals with hypertension diagnosed 2001-2008 in the Swedish Primary Care Cardiovascular Database assessed mortality by the Swedish Cause of Death Register, and myocardial infarction and ischemic stroke by the National Patient Register. Cox regression models were used to estimate study outcome hazard ratios by country of birth and time updated diabetes status, with adjustments for multiple confounders.

RESULTS

During follow-up time without diabetes using Swedish-born as reference, adjusted mortality hazard ratios per country of birth category were Finland: 1.26 (95% confidence interval 1.15-1.38), high-income European countries: 0.84 (0.74-0.95), low-income European countries: 0.84 (0.71-1.00) and non-European countries: 0.65 (0.56-0.76). The corresponding adjusted mortality hazard ratios during follow-up time with diabetes were high-income European countries: 0.78 (0.63-0.98), low-income European countries: 0.74 (0.57-0.96) and non-European countries: 0.56 (0.44-0.71). During follow-up without diabetes, the corresponding adjusted hazard ratio of myocardial infarction was increased for Finland: 1.16 (1.01-1.34), whereas the results for ischemic stroke were inconclusive.

CONCLUSION

In Sweden, hypertensive immigrants (with the exception for Finnish-born) with and without diabetes have a mortality advantage, as compared to Swedish-born.

Multimorbidity and chronic diseases among undocumented migrants: evidence to contradict the myths

Background

There is little verified information on the global health status of undocumented migrants (UMs). Our aim is to compare the prevalence of the main chronic diseases and of multimorbidity in undocumented migrants, documented migrants, and Spanish nationals in a Spanish autonomous community.

Methods

Retrospective observational study of all users of the public health system of the region of Aragon over 1 year (2011): 930,131 Spanish nationals; 123,432 documented migrants (DMs); and 17,152 UMs. Binary logistic regression was performed to examine the association between migrant status (Spanish nationals versus DMs and UMs) and both multimorbidity and individual chronic diseases, adjusting for age and sex.

Results

The prevalence of individual chronic diseases in UMs was lower than in DMs and much lower than in Spanish nationals. Comparison with the corresponding group of Spanish nationals revealed odds ratios (OR) of 0.1–0.3 and 0.3–0.5 for male and female UMs, respectively (p < 0.05 in all cases). The risk of multimorbidity was lower for UMs than DMs, both for men (OR, 0.12; 95%CI 0.11–0.13 versus OR, 0.53; 95%CI 0.51–0.54) and women (OR, 0.18; 95%CI 0.16–0.20 versus OR, 0.74; 95%CI 0.72–0.75).

Conclusions

Analysis of data from a health system that offers universal coverage to all immigrants, irrespective of legal status, reveals that the prevalence of chronic disease and multimorbidity is lower in UMs as compared with both DMs and Spanish nationals. These findings refute previous claims that the morbidity burden in UM populations is higher than that of the native population of the host country.

Socio-Demographic Determinants of Mortality from Chronic Noncommunicable Diseases in Women of Reproductive Age in the Republic of Georgia: Evidence from the National Reproductive Age Mortality Study (2014)

Purpose

Worldwide, noncommunicable diseases (NCDs) are the leading cause of premature death of women, taking the highest toll in developing countries. This study aimed to identify key socio-demographic determinants of NCD mortality in reproductive-aged women (15-49 years) in Georgia.

Materials and Methods

The study employed the verbal autopsy data from the second National Reproductive Age Mortality Survey 2014. Univariate and multivariate logistic regression models were fitted to explore the association between each risk factor and NCD mortality, measured by crude and adjusted odds ratio (AOR) with respective 95% confidence intervals (95% CI).

Results

In the final sample of 843 women, 586 (69.5%) deaths were attributed to NCDs, the majority of which occurred outside a hospital (72.7%) and among women aged 45-49 years (46.8%), ethnic Georgians (85.2%), urban residents (60.1%), those being married (60.6%), unemployed (75.1%) or having secondary and higher education (69.5%), but with nearly equal distribution across the wealth quintiles. After multivariate adjustment, the odds of dying from NCDs were significantly higher in women aged 45-49 years (AOR=17.69, 95% CI= 9.35 to 33.50), those being least educated (AOR=1.55, 95% CI= 1.01 to 2.37) and unemployed (AOR=1.47, 95% CI= 1.01 to 2.14) compared, respectively, to their youngest (15-24 years), more educated and employed counterparts. Strikingly, the adjusted odds were significantly lower in "other" ethnic minorities (AOR=0.29, 95% CI= 0.14 to 0.61) relative to ethnic Georgians. Contrariwise, there were no significant associations between NCD mortality and women's marital or wealth status, place of residence (rural/urban) or place of death.

Conclusion

Age, ethnicity, education, and employment were found to be strong independent predictors of young women's NCD mortality in Georgia. Further research on root causes of inequalities in mortality across the socioeconomic spectrum is warranted to inform equity- and life course-based multisectoral, integrated policy responses that would be conducive to enhancing women's survival during and beyond reproduction.

Intended place of residence in old age of internal migrants aged 15-64 years: a citywide cross-sectional study in Shanghai, China

OBJECTIVES

To explore the intentions of working-age internal migrants concerning their place of residence in old age and the relevant influencing factors.

METHOD

A cross-sectional survey was conducted in the 17 districts of Shanghai, China in 2013. Through multi-stage stratified sampling with probability proportional to size, 7968 internal migrants (aged 15-64 years) were selected and interviewed individually face to face. The primary outcome concerned the intended place of residence in old age of internal migrants living in Shanghai. Information was collected on demographic characteristics, health insurance, economic condition and participation in social activities. Multinomial logistic regression was performed to analyse the factors influencing migrants' intentions concerning their place of residence in old age.

RESULTS

A total of 7927 working-age migrants with complete data were analysed. Of these, 57.0% intended to live in their hometown in old age, 17.7% planned to remain in Shanghai and 25.3% were undecided. Those respondents who were male, less educated, from rural areas or Western China, living in rental houses or who had left family members behind in their hometowns were more likely to choose their hometown as their intended residence in old age (p<0.05). Engagement in business, longer residence duration, possession of social insurance and participation in social activities in Shanghai were identified as possible motivators for migrants who intended to remain in Shanghai in old age (p<0.05).

CONCLUSIONS

Most of the migrants expressed an intention to remigrate to their hometowns in old age. Education, economic capacity and social insurance influenced internal migrants in their decision. Relevant authorities should monitor the remigration pattern of ageing migrants, strengthen the senior care system and prepare health service resources that are more adequate, especially in the provinces or cities whence the migrants came.

Bias in cohort-based comparisons of immigrants' health outcomes between countries: a simulation study

Background

Cohort-type data are increasingly used to compare health outcomes of immigrants between countries, e.g. to assess the effects of different national integration policies. In such international comparisons, small differences in cardiovascular diseases risk or mortality rates have been interpreted as showing effects of different policies. We conjecture that cohort-type data sets available for such comparisons might not provide unbiased relative risk estimates between countries because of differentials in migration patterns occurring before the cohorts are being observed.

Method

Two simulation studies were performed to assess whether comparisons are biased if there are differences in 1. the way migrants arrived in the host countries, i.e. in a wave or continuously; 2. the effects on health of exposure to the host country; or 3., patterns of return-migration before a cohort is recruited. In the first simulation cardiovascular disease was the outcome and immortality in the second. Bias was evaluated using a Cox regression model adjusted for age and other dependant variables.

Results

Comparing populations from wave vs. continuous migration may lead to bias only if the duration of stay has a dose-response effect (increase in simulated cardiovascular disease risk by 5% every 5 years vs. no risk: hazard-ratio 1.20(0.15); by 10% every 5 years: 1.47(0.14)). Differentials in return-migration patterns lead to bias in mortality rate ratios (MRR). The direction (under- or overestimation) and size of the bias depends on the model (MRR from 0.92(0.01) to 1.09(0.01)).

Conclusion

The order of magnitude of the effects interpreted as due to integration policies in the literature is the same as the bias in our simulations. Future studies need to take into account duration and relevance of exposure and return-migration to make valid inferences about the effects of integration policies on the health of immigrants.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7267-2) contains supplementary material, which is available to authorized users.

Migrant mortality differences in the 2000s in Belgium: interaction with gender and the role of socioeconomic position

Background

Belgium has a long history of migration. As the migrant population is ageing, it is crucial thoroughly to document their health. Many studies that have assessed this, observed a migrant mortality advantage. This study will extend the knowledge by probing into the interaction between migrant mortality and gender, and to assess the role of socioeconomic position indicators in this paradox.

Methods

Individually linked data of the 2001 Belgian Census, the National Register and death certificates for 2001–2011 were used. Migrant origin was based on both own and parents’ origin roots. We included native Belgians and migrants from the largest migrant groups aged 25 to 65 years. Absolute and relative mortality differences by migrant origin were calculated for the most common causes of death. Moreover, the Poisson models were adjusted for educational attainment, home ownership and employment status.

Results

We observed a migrant mortality advantage for most causes of death and migrant groups, which was strongest among men. Adjusting for socioeconomic position generally increased the migrant mortality advantage, however with large differences by gender, migrant origin, socioeconomic position indicator and causes of death.

Conclusions

Adjusting for socioeconomic position even accentuated the migrant mortality advantage although the impact varied by causes of death, migrant origin and gender. This highlights the importance of including multiple socioeconomic position indicators when studying mortality inequalities. Future studies should unravel morbidity patterns too since lower mortality not necessarily implies better health. The observed migrant mortality advantage suggests there is room for improvement. However, it is essential to organize preventative and curative healthcare that is equally accessible across social and cultural strata.

Trends in Belgian cause-specific mortality by migrant origin between the 1990s and the 2000s

Background

Belgium has a large migrant community that is increasingly ageing. As migrants may have faced environmental and social exposures before, during and after migration, they may have experienced an accelerated epidemiological transition. Studying mortality differentials between the migrant and native population may therefore allow for a better understanding of the aetiology of diseases. While many studies have assessed migrant mortality, few have looked into the role of gender or the trend over time. Therefore, this study aims to probe into mortality differences between the native and migrant population for all major causes of death (COD) during the 1990s and 2000s. We will discriminate between all major migrant groups and men and women as they have different migration histories.

Methods

Individually linked data of the Belgian Census, the National Register and death certificates for the periods 1991–1997 and 2001–2008 were used. Migrant origin was based on both own and parents’ origin, hereby maximizing the population with migrant roots. We included native Belgians and migrants from the largest migrant groups aged 25 to 65 years. Both absolute and relative mortality differences by migrant origin were calculated for the most common COD.

Results

We generally observed a migrant advantage for overall, cause-specific and cancer-specific mortality, with infection-related cancer mortality being the only exception. The effect was particularly strong for lifestyle-related COD, non-western migrants, and men. Over time, mortality declined among native Belgian men and women, yet remained stable for several migrant groups. This converging trend was largely due to smoking and reduced reproductive behaviour among migrants.

Conclusions

The migrant mortality advantage stresses that there is room for improvement in the area of health in Belgium. Since the largest differences between native Belgians and migrants were observed for lifestyle-related diseases, and there is a tendency towards convergence of mortality over time, primary prevention tackling the most vulnerable groups remains crucial. Moreover, efforts should be made to ensure equal access to health care among the social and cultural strata.

Does ethnic diversity explain intra-UK variation in mortality? A longitudinal cohort study

OBJECTIVES

It has been proposed that part of the explanation for higher mortality in Scotland compared with England and Wales, and Glasgow compared with other UK cities, relates to greater ethnic diversity in England and Wales. We sought to assess the extent to which this excess was attenuated by adjusting for ethnicity. We additionally explored the role of country of birth in any observed differences.

SETTING

Scotland and England and Wales; Glasgow and Manchester.

PARTICIPANTS

We used the Scottish Longitudinal Study and the Office for National Statistics Longitudinal Study of England and Wales (2001-2010). Participants (362 491 in total) were aged 35-74 years at baseline.

PRIMARY OUTCOME MEASURES

Risk of all-cause mortality between 35 and 74 years old in Scotland and England and Wales, and in Glasgow and Manchester, adjusting for age, gender, socioeconomic position (SEP), ethnicity and country of birth.

RESULTS

18% of the Manchester sample was non-White compared with 3% in Glasgow (England and Wales: 10.4%; Scotland: 1.2%). The mortality incidence rate ratio was 1.33 (95% CI 1.13 to 1.56) in Glasgow compared with Manchester. This reduced to 1.25 (1.07 to 1.47) adjusting for SEP, and to 1.20 (1.02 to 1.42) adjusting for ethnicity and country of birth. For Scotland versus England and Wales, the corresponding figures were 18% higher mortality, reducing to 10%, and then 7%. Non-Whites born outside the UK had lower mortality. In the Scottish samples only, non-Whites born in the UK had significantly higher mortality than Whites born in the UK.

CONCLUSIONS

The research supports the hypothesis that ethnic diversity and migration from outside UK play a role in explaining Scottish excess mortality. In Glasgow especially, however, a large excess remains: thus, previously articulated policy implications (addressing poverty, vulnerability and inequality) still apply.

Dementia in immigrant groups: A cohort study of all adults 45 years of age and older in Sweden

OBJECTIVE

To study the association between country of birth and incident dementia in several immigrant groups in Sweden.

METHODS

The study population included all adults (n = 3,286,624) aged 45 years and older in Sweden. Dementia was defined as having at least one registered diagnosis of dementia in the National Patient Register. The incidence of dementia in different immigrant groups, using Swedish-born as referents, was assessed by Cox regression, expressed in hazard ratios (HRs) and 95% confidence intervals (CI). All models were stratified by sex and adjusted for age, geographical residence in Sweden, educational level, marital status, and neighbourhood socioeconomic status.

RESULTS

A total of 136,713 individuals had a registered dementia event, i.e. 4.2%; 3.6% among men and 4.9% among women. After adjusting for confounders, in general, there was a lower incidence of dementia among both male immigrants (HR 0.85, 0.83-0.88) and female immigrants (HR 0.93, 0.91-0.95) compared to their Swedish-born counterparts. Among immigrant groups, a higher incidence (HR, 95%CI) of dementia was observed among men from Finland (1.14, 1.08-1.20), Bosnia (1.61, 1.18-2.20), Estonia (1.25, 1.10-1.43) and Russia (1.37, 1.12-1.69), and women from Finland (1.20 1.15-1.24) and Norway (1.14, 1.07-1.22).

CONCLUSIONS

Risk of dementia was lower in immigrants in general compared to the Swedish-born population; however there were substantial differences among immigrant groups in risk of dementia. Developing dementia in a new country with a different language could cause problems for both patients and the health care staff.

The definition of immigrant status matters: impact of nationality, country of origin, and length of stay in host country on mortality estimates

BACKGROUND

Mortality is a robust indicator of health and offers valuable insight into the health of immigrants. However, mortality estimates can vary significantly depending on the manner in which immigrant status is defined. Here, we assess the impact of nationality, country of origin, and length of stay in the host country on mortality estimates in an immigrant population in Aragón, Spain.

METHODS

Cross-sectional retrospective study of all adult subjects from the EpiChron Cohort in 2011 (n = 1,102,544), of whom 146,100 were foreign-born (i.e., according to place of birth) and 127,213 were non-nationals (i.e., according to nationality). Directly standardized death proportions between years 2012-2015 were calculated, taking into account the age distribution of the European population in 2013. Binary logistic regression was used to compare the four-year probability of death.

RESULTS

The age- and sex-standardized number of deaths per 1000 subjects were 45.1 (95%CI 44.7-45.2) for the Spanish-born population, 29.3 (95%CI 26.7-32.1) for the foreign-born population, and 18.4 (95%CI 15.6-21.6) for non-Spanish nationals. Compared with the Spanish-born population, the age- and sex-adjusted likelihood of dying was equally reduced in the foreign-born and non-national populations (OR 0.6; 95%CI 0.5-0.7) when the length of stay was less than 10 years. No significant differences in mortality estimates were detected when the length of stay was over 10 years.

CONCLUSIONS

Mortality estimates in immigrant populations were lower than those of the native Spanish population, regardless of the criteria applied. However, the proportion of deaths was lower when immigrant status was defined using nationality instead of country of birth. Age- and sex-standardized death proportions tended to increase with increased length of stay in the host country.

Differences in cancer survival between immigrants in Norway and the host population

Cancer survival is an important indicator for quality of cancer care. We sought to determine if there are differences in cancer survival between immigrants and the host population in Norway. We performed a nationwide registry-based study comprising subjects diagnosed with cancer between 1990 and 2014, and followed until the end of 2016. Survival was estimated for 13 cancer sites with cause-specific survival. Adjustments were made for common confounders (age, sex, year of diagnosis and place of residence) and defined mediators (stage at diagnosis, comorbidity and socioeconomic factors). A total of 500,255 subjects were available for analysis, of which 11,252 were Western and 8,701 non-Western immigrants. We did not find differences in cancer survival between Western immigrants and Norwegians, while non-Western immigrants, with some exceptions, had similar or better survival. Better lung cancer survival in non-Western immigrants than Norwegians was notable (hazard ratio (95% confidence interval): 0.78 (0.71-0.85)), and not explained by defined mediators. Immigrants from Eastern Europe and Balkan with melanoma (hazard ratio: 1.54 (1.12-2.12)) and prostate cancer (hazard ratio: 1.34 (1.08-1.67)), and possibly from sub-Saharan Africa with breast cancer (hazard ratio: 1.41 (0.94-2.12)) had worse survival than Norwegians. The results suggest that immigrants in Norway have good cancer survival relative to the host population. Poor survival in immigrants from Eastern Europe and Balkan with melanoma and prostate cancer, and sub-Saharan Africa with breast cancer might be a concern.

Employment status and risk of all-cause mortality among native- and foreign-origin persons in Sweden

Background

The association between exposure to unemployment and increased risk of mortality is well established. Yet migrants and their children often experience a number of stressors in the country of residence which could exacerbate the negative effects of job loss or unemployment. This study examined the extent to which region of origin and generational status modified associations between employment status and risk of all-cause mortality.

Methods

Using population-based registers, an open cohort of 2 178 321 individuals aged 25-64 years was followed from 1993 to 2008. Hazard ratios for mortality were calculated using Cox regression. Employment status and socio-demographic covariates were included as time-varying variables in all models.

Results

Relative to employed native-origin Swedes, excess risk of mortality was found among most groups of unemployed persons. The excess risk of mortality found among African women exposed to long-term unemployment (HR = 3.26, 95% CI: 2.30-4.63), Finnish men exposed to short-and long-term unemployment (HR = 2.74, 95% CI: 2.32-3.24 and HR = 2.39, 95% CI: 2.12-2.69), and second generation Swedish men exposed to short-term unemployment (HR = 2.34, 95% CI: 2.06-2.64) was significantly greater (P < 0.05) than that found among their unemployed native-origin counterparts. Excess risk of mortality among the unemployed in other foreign-origin groups was of a similar or lower magnitude to that found in unemployed native-origin Swedes. A decreased risk of mortality was observed among the employed in nearly all foreign-origin groups.

Conclusions

With some exceptions, mortality risk in foreign-origin individuals across all categories of employment status was generally similar to or lower than the risk observed in native-origin Swedes.

All-cause mortality, age at arrival, and duration of residence among adult migrants in Sweden: A population-based longitudinal study

Background

A mortality advantage has been observed among recently arrived immigrants in multiple national contexts, even though many immigrants experience more social disadvantage compared to natives. This is the first study to investigate the combined influence of duration of residence and age at arrival on the association between region of origin and all-cause mortality among the adult immigrant population in Sweden.

Methods

Using population-based registers, we conducted a follow-up study of 1,363,429 individuals aged 25–64 years from 1990 to 2008. Gompertz parametric survival models were fitted to derive hazard ratios (HR) for all-cause mortality.

Results

Compared to native Swedes, we observed a health advantage in all group of immigrants, with the exception of individuals from Finland. However, when information on age at arrival and duration of residence was combined, an excess mortality risk was found among immigrants who arrived before age 18, which largely disappeared after 15 years of residence in Sweden. Non-European immigrants over age 18 showed similar or lower mortality risks than natives in all categories of age at arrival, regardless of duration of residence.

Conclusions

The findings suggest that the mortality advantage commonly observed among immigrants is not universal. Combined information on age at arrival and duration of residence can be used to identify sensitive periods and to identify possible selection bias. The study also suggests that young immigrants are a vulnerable subpopulation. Given the increased number of unaccompanied minors arriving in Europe, targeted health or integration policies should be developed or reviewed.

•

Age at arrival and duration of residence modify immigrant’s risk of mortality.

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There is an excess mortality risk among immigrants who arrived in Sweden as minors.

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This excess risk was less evident in immigrants with 15 years or more of residence in Sweden.

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Age at arrival and duration of residence can be used to identify sensitive periods.

An observational study of immigrant mortality differences in Norway by reason for migration, length of stay and characteristics of sending countries

BACKGROUND

Knowledge of mortality differentials in immigrant groups depending on their reason for migration, length of stay in host countries and characteristics of sending countries may be beneficial for policy interventions aimed to improve various immigrant groups' health and welfare.

METHODS

We employed discrete-time hazard regression models with time-varying covariates to compare the death risk of immigrants to those of Norwegian-born natives using linked register data on the Norwegian population aged 25-79 during 1990-2015. More than 492,000 deaths occurred in around 4.6 million individuals. All analyses were adjusted for sex, age, calendar time and sociodemographic characteristics.

RESULTS

Immigrants had an 11% survival advantage overall. Those immigrating due to work or education had the lowest death risk, whereas refugees had the highest death risk (albeit lower than that of natives). Death risks increased markedly with length of stay, and were most pronounced for those having spent more than 40% of their lives in Norway. Net of reason for migration, only minor differences were observed depending on Human Development Index characteristics of sending countries.

CONCLUSION

Independent of reason for migration and characteristics of sending countries, those who immigrate to Norway in adulthood appear to be particularly healthy. The higher death risk associated with prolonged lengths of stay suggests that disadvantageous 'acculturation' or stress factors related to the post-migration period may play a role in the long run. The health and welfare of long-term immigrants thus warrants further research.

Mortality, ethnicity, and country of birth on a national scale, 2001-2013: A retrospective cohort (Scottish Health and Ethnicity Linkage Study)

BACKGROUND

Migrant and ethnic minority groups are often assumed to have poor health relative to the majority population. Few countries have the capacity to study a key indicator, mortality, by ethnicity and country of birth. We hypothesized at least 10% differences in mortality by ethnic group in Scotland that would not be wholly attenuated by adjustment for socio-economic factors or country of birth.

METHODS AND FINDINGS

We linked the Scottish 2001 Census to mortality data (2001-2013) in 4.62 million people (91% of estimated population), calculating age-adjusted mortality rate ratios (RRs; multiplied by 100 as percentages) with 95% confidence intervals (CIs) for 13 ethnic groups, with the White Scottish group as reference (ethnic group classification follows the Scottish 2001 Census). The Scottish Index of Multiple Deprivation, education status, and household tenure were socio-economic status (SES) confounding variables and born in the UK or Republic of Ireland (UK/RoI) an interacting and confounding variable. Smoking and diabetes data were from a primary care sub-sample (about 53,000 people). Males and females in most minority groups had lower age-adjusted mortality RRs than the White Scottish group. The 95% CIs provided good evidence that the RR was more than 10% lower in the following ethnic groups: Other White British (72.3 [95% CI 64.2, 81.3] in males and 75.2 [68.0, 83.2] in females); Other White (80.8 [72.8, 89.8] in males and 76.2 [68.6, 84.7] in females); Indian (62.6 [51.6, 76.0] in males and 60.7 [50.4, 73.1] in females); Pakistani (66.1 [57.4, 76.2] in males and 73.8 [63.7, 85.5] in females); Bangladeshi males (50.7 [32.5, 79.1]); Caribbean females (57.5 [38.5, 85.9]); and Chinese (52.2 [43.7, 62.5] in males and 65.8 [55.3, 78.2] in females). The differences were diminished but not eliminated after adjusting for UK/RoI birth and SES variables. A mortality advantage was evident in all 12 minority groups for those born abroad, but in only 6/12 male groups and 5/12 female groups of those born in the UK/RoI. In the primary care sub-sample, after adjustment for age, UK/RoI born, SES, smoking, and diabetes, the RR was not lower in Indian males (114.7 [95% CI 78.3, 167.9]) and Pakistani females (103.9 [73.9, 145.9]) than in White Scottish males and females, respectively. The main limitations were the inability to include deaths abroad and the small number of deaths in some ethnic minority groups, especially for people born in the UK/RoI.

CONCLUSIONS

There was relatively low mortality for many ethnic minority groups compared to the White Scottish majority. The mortality advantage was less clear in UK/RoI-born minority group offspring than in immigrants. These differences need explaining, and health-related behaviours seem important. Similar analyses are required internationally to fulfil agreed goals for monitoring, understanding, and improving health in ethnically diverse societies and to apply to health policy, especially on health inequalities and inequities.

Multimorbidity and immigrant status: associations with area of origin and length of residence in host country

AIM

Multimorbidity is a growing phenomenon in primary care, and knowledge of the influence of social determinants on its evolution is vital. The aim of this study was to understand the relationship between multimorbidity and immigration, taking into account length of residence in the host country and area of origin of the immigrant population.

METHODS

Cross-sectional retrospective study of all adult patients registered within the public health service of Aragon, Spain (N = 1092279; 144238 were foreign-born), based on data from the EpiChron Cohort. Age-standardized prevalence rates of multimorbidity were calculated. Different models of binary logistic regressions were conducted to study the association between multimorbidity, immigrant status and length of residence in the host country.

RESULTS

The risk of multimorbidity in foreign-borns was lower than that of native-borns [odds ratio (OR): 0.54, 95% confidence interval (CI): 0.53-0.55]. The probability of experiencing multimorbidity was lowest for Asians (OR: 0.34, 95% CI: 0.31-0.37) and Eastern Europeans (OR: 0.42, 95% CI: 0.40-0.43), and highest for Latin Americans (OR: 0.70, 95% CI: 0.68-0.72). Foreign-born immigrants residing in Aragon for ≥5 years had a higher multimorbidity risk than those residing for <5 years (OR: 2.3, 95% CI: 2.2-2.4).

CONCLUSION

Prevalence of multimorbidity is lower among foreign-borns as compared with native-borns, but increases rapidly with length of residence in the host country. However, the progressive development of multimorbidity among immigrants varies widely depending on area of origin. These findings provide important insight into the health care needs of specific population groups and may help minimize the negative impact of multimorbidity among the most vulnerable groups.

Role of disease and demographic factors as determinants of return migration: A nationwide register-based cohort study

AIMS

A number of aspects of the health status of migrants who return to their country of origin have been explored in the literature; however, a more general description of the incidence of disease and demographic characteristics is lacking. The aim of this research was to contribute such a description.

METHODS

A nationwide cohort study was conducted of 114,331 migrants who obtained residence in Denmark between 1 January 1993 and 31 December 2010. Demographic characteristics and ten disease groups were included as explanatory variables and hazards ratios for the association between return migration and disease incidence, as well as demographic characteristics, were estimated using Cox regressions.

RESULTS

The tendency to return-migrate when ill was not the same among younger and elderly migrants; migrants <55 years of age had a significantly smaller propensity to return-migrate if they had suffered from a disease during the 18 years of follow-up compared with those who had not had a disease, whereas migrants ≥55 years of age were more prone to return if ill. The likelihood of returning decreased with increasing comorbidity in both age groups. Among those who were <55 years of age, the tendency to return increased with age at obtainment of residence; among those who were ≥55 years, more men than women return-migrated.

CONCLUSIONS

In Denmark, younger migrants are less inclined to return-migrate if they are ill compared with healthy migrants, whereas elderly migrants are more inclined to return if ill. The returnees also differ demographically from non-returnees in various ways.

Distinctive role of income in the all-cause mortality among working age migrants and the settled population in Finland: A follow-up study from 2001 to 2014

BACKGROUND

Although income level may play a significant part in mortality among migrants, previous research has not focused on the relationship between income, migration and mortality risk. The aim of this register study was to compare all-cause mortality by income level between different migrant groups and the majority settled population of Finland.

METHODS

A random sample was drawn of 1,058,391 working age people (age range 18-64 years; 50.4% men) living in Finland in 2000 and linked to mortality data from 2001 to 2014. The data were obtained from Statistics Finland. Cox proportional hazards models were used to investigate the association between region of origin and all-cause mortality in low- and high-income groups.

RESULTS

The risk for all-cause mortality was significantly lower among migrants than among the settled majority population (hazards ratio (HR) 0.57; 95% confidence interval (CI) 0.53-0.62). After adjustment for age, sex, marital status, employment status and personal income, the risk of mortality was significantly reduced for low-income migrants compared with the settled majority population with a low income level (HR 0.46; 95% CI 0.42-0.50) and for high-income migrants compared with the high-income settled majority (HR 0.81; 95% CI 0.69-0.95). Results comparing individual high-income migrant groups and the settled population were not significant. Low-income migrants from Africa, the Middle East and Asia had the lowest mortality risk of any migrant group studied (HR 0.32; 95% CI 0.27-0.39).

CONCLUSIONS

Particularly low-income migrants seem to display a survival advantage compared with the corresponding income group in the settled majority population. Downward social mobility, differences in health-related lifestyles and the healthy migrant effect may explain this phenomenon.

Diabetes among migrants in Denmark: Incidence, mortality, and prevalence based on a longitudinal register study of the entire Danish population

OBJECTIVE

Studies of diabetes in migrant populations have shown a higher prevalence compared to their respective countries of origin and to people natively born in the host country, but there is little population-based data on diabetes incidence and mortality in migrant populations. The aim of the current study was (1) to describe the incidence rates and prevalence of diabetes among first generation migrants in Denmark compared to the Danish background population, and (2) to compare standardised mortality rates (SMRs) for individuals with and without diabetes according to country of origin.

RESEARCH DESIGN AND METHODS

Information was obtained from linkage of the National Diabetes Register with mortality statistics and information from the Central Personal Register on country of origin. Age- and sex-specific estimates of prevalence, incidence rates, mortality rates and SMRs relative to the part of the population without diabetes were calculated based on follow up of the entire Danish population.

RESULTS

Compared with native born Danes, the incidence of diabetes was about 2.5 times higher among migrants from Africa, Asia, and the Middle East, and these migrant groups also showed significantly higher prevalence. The standardised mortality rates (SMR) were higher particularly above 50years of age among most migrant groups compared with native born Danes, and with a higher annual increase.

CONCLUSIONS

The highest diabetes incidence rates and prevalence estimates were observed among migrants from Africa, Asia, and the Middle East, and the annual increase in SMRs was higher in these groups compared to native born Danes.

Aging and health among migrants in a European perspective

Population aging and the associated changes in demographic structures and healthcare needs is a key challenge across Europe. Healthy aging strategies focus on ensuring the ability to maintain health, quality of life and independent living at old age. Concurrent to the process of population aging, the demographics of Europe are affected by increased migration resulting in substantial ethnic diversity. In this paper, we narratively review the health profile of the growing proportion of aging migrants in Europe, outline key factors shaping health among this diverse group and consider ways of addressing their healthcare needs.

Although factors shaping aging processes are largely similar across populations, migrant-specific risk factors exist. These include exposure to health risks before and during migration; a more disadvantaged socioeconomic position; language barriers and low health literacy; cultural factors influencing health-seeking behaviours; and psychosocial vulnerability and discrimination affecting health and quality of life. Overall, migrants experience the same morbidity and mortality causes as the native populations, but with different relative importance, severity and age of onset and with substantial differences within and between migrant groups. Little is known regarding health behaviours among aging migrants, although differences in cancer screening behaviours have been identified. Indications of widening health differentials between migrants and native populations with age and informal barriers to quality healthcare for aging migrants are causes of concern.

In conclusion, there is a need for attention to migration alongside other determinants of healthy aging. The diversity in individual characteristics, life course processes and contextual factors shaping aging processes among migrants point to the need for a sensitive and comprehensive approach to policies, practices and research within the field of healthy aging. This is important to accommodate for the needs of the growing number of aging migrants in Europe and counter inequities in health and well-being at old age.

Return Migration to Mexico: Does Health Matter?

We use data from three rounds of the Mexican Family Life Survey to examine whether migrants in the United States returning to Mexico in the period 2005-2012 have worse health than those remaining in the United States. Despite extensive interest by demographers in health-related selection, this has been a neglected area of study in the literature on U.S.-Mexico migration, and the few results to date have been contradictory and inconclusive. Using five self-reported health variables collected while migrants resided in the United States and subsequent migration history, we find direct evidence of higher probabilities of return migration for Mexican migrants in poor health as well as lower probabilities of return for migrants with improving health. These findings are robust to the inclusion of potential confounders reflecting the migrants' demographic characteristics, economic situation, family ties, and origin and destination characteristics. We anticipate that in the coming decade, health may become an even more salient issue in migrants' decisions about returning to Mexico, given the recent expansion in access to health insurance in Mexico.

Refugee children have fewer contacts to psychiatric healthcare services: an analysis of a subset of refugee children compared to Danish-born peers

PURPOSE

Studies show a high level of mental health problems among refugee children. This study examined whether a subset of refugee children living in Denmark accessed psychiatric healthcare services more than those born in the country.

METHODS

This study compared 24,427 refugee children from Asia, The Middle East, Sub-Saharan Africa and former Yugoslavia, who obtained residency in Denmark between 1 January 1993 and 31 December 2010 with 146,562 Danish-born children, matched 1:6 on age and sex. The study looked at contacts with psychiatric hospitals as well as psychologists and psychiatrists in private practice.

RESULTS

Between 1 January 1996 and 30 June 2012, 3.5 % of the refugee children accessed psychiatric healthcare services compared to 7.7 % of the Danish-born children. The rate ratio of having any first-time psychiatric contact was 0.42 (95 % CI 0.40-0.45) among refugee boys and 0.35 (95 % CI 0.33-0.37) among refugee girls, compared to Danish-born children. Figures were similar for those accessing private psychologists or psychiatrists, emergency room, inpatient and outpatient services.

CONCLUSIONS

Refugee children used fewer psychiatric healthcare services than Danish-born children. This may indicate that refugee children experience barriers in accessing psychiatric healthcare systems and do not receive adequate assessment of their mental health and subsequent referral to specialist services.

Social and health epidemiology of immigrants in Germany: past, present and future

Germany has experienced different forms of immigration for many decades. At the end of and after the Second World War, refugees, displaced persons and German resettlers constituted the largest immigrant group. In the 1950s, labor migration started, followed by family reunification. There has been a constant migration of refugees and asylum seekers reaching peaks in the early 1990s as well as today. Epidemiological research has increasingly considered the health, and the access to health care, of immigrants and people with migration background. In this narrative review we discuss the current knowledge on health of immigrants in Germany. The paper is based on a selective literature research with a focus on studies using representative data from the health reporting system.

Our review shows that immigrants in Germany do not suffer from different diseases than non-immigrants, but they differ in their risk for certain diseases, in the resources to cope with theses risk and regarding access to treatment. We also identified the need for differentiation within the immigrant population, considering among others social and legal status, country of origin and duration of stay. Though most of the studies acknowledge the need for differentiation, the lack of data currently rules out analyses accounting for the existing diversity and thus a full understanding of health inequalities related to migration to Germany.

Life expectancy of different ethnic groups using death records linked to population census data for 4.62 million people in Scotland

Background

Few countries record the data needed to estimate life expectancy by ethnic group. Such information is helpful in assessing the extent of health inequality.

Method

Life tables were created using 3 years of deaths (May 2001–April 2004) linked to Scottish 2001 Census data for 4.62 million individuals with self-reported ethnicity. We created 8 ethnic groups based on the census definitions, each with at least 5000 individuals and 40 deaths. Life expectancy at birth was calculated using the revised Chiang method.

Results

The life expectancy of White Scottish males at birth was 74.7 years (95% CI 74.6 to 74.8), similar to Mixed Background (73.0; 70.2 to 75.8) and White Irish (75.0; 74.0 to 75.9), but shorter than Indian (80.9; 78.4 to 83.4), Pakistani (79.3; 76.9 to 81.6), Chinese (79.0; 76.5 to 81.5), Other White British (78.9; 78.6 to 79.2) and Other White (77.2; 76.4 to 78.1). The life expectancy of White Scottish females was 79.4 years (79.3 to 79.5), similar to mixed background (79.3; 76.6 to 82.0), but shorter than Pakistani (84.6; 82.0 to 87.3), Chinese (83.4; 81.1 to 85.7), Indian (83.3; 80.7 to 85.9), Other White British (82.6; 82.3 to 82.9), other White (82.0; 81.3 to 82.8) and White Irish (81; 80.2 to 81.8).

Conclusions

Males and females in most of the larger ethnic minority groups in Scotland have longer life expectancies than the majority White Scottish population.

Differences in mortality by immigrant status in Italy. Results of the Italian Network of Longitudinal Metropolitan Studies

Despite a rapid increase in immigration from low-income countries, studies on immigrants' mortality in Italy are scarce. We aimed to describe differences in all and cause-specific mortality among immigrants and Italians residing in Turin and Reggio Emilia (Northern Italy), two cities participating in the Italian Network of Longitudinal Metropolitan Studies (IN-LiMeS). We used individual data from the municipal population registers linked to the cause of death registers. All people aged 1-64 years residing between 2001 and 2010 were enrolled (open cohort) and followed up until 2013. The mortality of citizens from high migratory pressure countries (as a whole, and for each macro-area group) was compared with that of Italians; differences were estimated by Poisson regression adjusted by age and calendar year mortality rate ratios (MRRs), and by age-standardized mortality ratios for the analysis of cause-specific mortality. Compared with Italians, immigrants had lower overall mortality (MRR for men: 0.82, 95 % CI: 0.75-0.90; for women: 0.71, 95 % CI: 0.63-0.81). Sub-Saharan Africans experienced a significant higher mortality than Italians (MRR for men 1.29, 95 % CI: 1.03-1.61; for women: 1.70, 95 % CI: 1.22-2.36). Higher mortality for immigrants compared to Italians was observed for infectious diseases, congenital anomalies, some site-specific tumours and homicide mortality. Our study showed heterogeneity in mortality across the macro-areas of origin, and in particular Sub-Saharan Africans seemed to be a vulnerable population. The extension to other cohorts of IN-LiMeS will allow the health status of immigrants and vulnerable groups to be studied and monitored in more depth.

Ethnic variations in asthma hospital admission, readmission and death: a retrospective, national cohort study of 4.62 million people in Scotland

BACKGROUND

Our previous meta-analysis found that South Asians and Blacks in the UK were at a substantially increased risk of hospital admission from asthma. These estimates were, however, derived from pooling data from a limited number of now dated studies, confined to only three very broad ethnic groups (i.e. Whites, South Asians and Blacks) and failed to take account of possible sex-related differences in outcomes within these ethnic groups. We undertook the first study investigating ethnic variations in asthma outcomes across an entire population.

METHODS

This retrospective 9-year cohort study linked Scotland's hospitalisation/death records on asthma to the 2001 census (providing ethnic group). We calculated age, country of birth and Scottish Index of Multiple Deprivation adjusted incident rate ratios (IRRs) for hospitalisation or death by sex for the period May 2001-2010. We calculated hazard ratios (HRs) for asthma readmission and subsequent asthma death.

RESULTS

We were able to link data on 4.62 million people (91.8% of the Scottish population), yielding over 38 million patient-years of data, 1,845 asthma deaths, 113,795 first asthma admissions, and 107,710 readmissions (40,075 of which were for asthma). There were substantial ethnic variations in the rate of hospitalisation/death in both males and females. When compared to the reference Scottish White population, the highest age-adjusted rates were in Pakistani males (IRR = 1.59; 95% CI, 1.30-1.94) and females (IRR = 1.50; 95% CI, 1.06-2.11) and Indian males (IRR = 1.34; 95% CI, 1.16-1.54), and the lowest were seen in Chinese males (IRR = 0.62; 95% CI, 0.41-0.94) and females (IRR = 0.49; 95% CI, 0.39-0.61).

CONCLUSION

There are very substantial ethnic variations in hospital admission/deaths from asthma in Scotland, with Pakistanis having the worst and Chinese having the best outcomes. Cultural factors, including self-management and health seeking behaviours, and variations in the quality of primary care provision are the most likely explanations for these differences and these now need to be formally investigated.

Ethnic inequalities in acute myocardial infarction and stroke rates in Norway 1994-2009: a nationwide cohort study (CVDNOR)

Background

Immigrants to Norway from South Asia and Former Yugoslavia have high levels of cardiovascular disease (CVD) risk factors. Yet, the incidence of CVD among immigrants in Norway has never been studied. Our aim was to study the burden of acute myocardial infarction (AMI) and stroke among ethnic groups in Norway.

Methods

We studied the whole Norwegian population (n = 2 637 057) aged 35–64 years during 1994–2009. The Cardiovascular Disease in Norway (CVDNOR) project provided information about all AMI and stroke hospital stays for this period, as well as deaths outside hospital through linkage to the Cause of Death Registry. The direct standardization method was used to estimate age standardized AMI and stroke event rates for immigrants and ethnic Norwegians. Rate ratios (RR) with ethnic Norwegians as reference were calculated using Poisson regression.

Results

The highest risk of AMI was seen in South Asians (men RR = 2.27; 95 % CI 2.08–2.49; women RR = 2.10; 95 % CI 1.76–2.51) while the lowest was seen in East Asians (RR = 0.38 in both men (95 % CI 0.25–0.58) and women (95 % CI 0.18–0.79)). Immigrants from Former Yugoslavia and Central Asia also had increased risk of AMI compared to ethnic Norwegians. South Asians had increased risk of stroke (men RR = 1.26; 95 % CI 1.10–1.44; women RR = 1.58; 95 % CI 1.32–1.90), as did men from Former Yugoslavia, Sub-Saharan Africa and women from Southeast Asia.

Conclusions

Preventive measures should be aimed at reducing the excess numbers of CVD among immigrants from South Asia and Former Yugoslavia.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2412-z) contains supplementary material, which is available to authorized users.

Mortality in adult immigrants in the 2000s in Belgium: a test of the 'healthy-migrant' and the 'migration-as-rapid-health-transition' hypotheses

OBJECTIVE

Firstly, to map out and compare all-cause and cause-specific mortality patterns by migrant background in Belgium; and secondly, to probe into explanations for the observed patterns, more specifically into the healthy-migrant, acculturation and the migration-as-rapid-health-transition theories.

METHODS

Data comprise individually linked Belgian census-mortality follow-up data for the period 2001-2011. All official inhabitants aged 25-54 at time of the census were included. To delve into the different explanations, differences in all-cause and chronic- and infectious-disease mortality were estimated using Poisson regression models, adjusted for age, socioeconomic position and urbanicity.

RESULTS

First-generation immigrants have lower all-cause and chronic-disease mortality than the host population. This mortality advantage wears off with length of stay and is more marked among non-Western than Western first-generation immigrants. For example, Western and non-Western male immigrants residing 10 years or more in Belgium have a mortality rate ratio for cardiovascular disease of 0.72 (95% CI 0.66-0.78) and 0.59 (95% CI 0.53-0.66), respectively (vs host population). The pattern of infectious-disease mortality in migrants is slightly different, with rather high mortality rates in first-generation sub-Saharan Africans and rather low rates in all other immigrant groups. As for second-generation immigrants, the picture is gloomier, with a mortality disadvantage that disappears after control for socioeconomic position.

CONCLUSION

Findings are largely consistent with the healthy-migrant, acculturation and the migration-as-rapid-health-transition theories. The convergence of the mortality profile of second-generation immigrants towards that of the host population with similar socioeconomic position indicates the need for policies simultaneously addressing different areas of deprivation.

All-cause and cause-specific mortality of different migrant populations in Europe

This study aimed to examine differences in all-cause mortality and main causes of death across different migrant and local-born populations living in six European countries. We used data from population and mortality registers from Denmark, England & Wales, France, Netherlands, Scotland, and Spain. We calculated age-standardized mortality rates for men and women aged 0-69 years. Country-specific data were pooled to assess weighted mortality rate ratios (MRRs) using Poisson regression. Analyses were stratified by age group, country of destination, and main cause of death. In six countries combined, all-cause mortality was lower for men and women from East Asia (MRRs 0.66; 95 % confidence interval 0.62-0.71 and 0.76; 0.69-0.82, respectively), and Other Latin America (0.44; 0.42-0.46 and 0.56; 0.54-0.59, respectively) than local-born populations. Mortality rates were similar for those from Turkey. All-cause mortality was higher in men and women from North Africa (1.09; 1.08-1.11 and 1.19; 1.17-1.22, respectively) and Eastern Europe (1.30; 1.27-1.33 and 1.05; 1.01-1.08, respectively), and women from Sub-Saharan Africa (1.34; 1.30-1.38). The pattern differed by age group and country of destination. Most migrants had higher mortality due to infectious diseases and homicide while cancer mortality and suicide were lower. CVD mortality differed by migrant population. To conclude, mortality patterns varied across migrant populations in European countries. Future research should focus both on migrant populations with favourable and less favourable mortality pattern, in order to understand this heterogeneity and to drive policy at the European level.

Health inequality between immigrants and natives in Spain: the loss of the healthy immigrant effect in times of economic crisis

BACKGROUND

The immigrant population living in Spain grew exponentially in the early 2000s but has been particularly affected by the economic crisis. This study aims to analyse health inequalities between immigrants born in middle- or low-income countries and natives in Spain, in 2006 and 2012, taking into account gender, year of arrival and socioeconomic exposures.

METHODS

Study of trends using two cross-sections, the 2006 and 2012 editions of the Spanish National Health Survey, including residents in Spain aged 15-64 years (20 810 natives and 2950 immigrants in 2006, 14 291 natives and 2448 immigrants in 2012). Fair/poor self-rated health, poor mental health (GHQ-12 > 2), chronic activity limitation and use of psychotropic drugs were compared between natives and immigrants who arrived in Spain before 2006, adjusting robust Poisson regression models for age and socioeconomic variables to obtain prevalence ratios (PR) and 95% confidence interval (CI).

RESULTS

Inequalities in poor self-rated health between immigrants and natives tend to increase among women (age-adjusted PR2006 = 1.39; 95% CI: 1.24-1.56, PR2012 = 1.56; 95% CI: 1.33-1.82). Among men, there is a new onset of inequalities in poor mental health (PR2006 = 1.10; 95% CI: 0.86-1.40, PR2012 = 1.34; 95% CI: 1.06-1.69) and an equalization of the previously lower use of psychotropic drugs (PR2006 = 0.22; 95% CI: 0.11-0.43, PR2012 = 1.20; 95% CI: 0.73-2.01).

CONCLUSIONS

Between 2006 and 2012, immigrants who arrived in Spain before 2006 appeared to worsen their health status when compared with natives. The loss of the healthy immigrant effect in the context of a worse impact of the economic crisis on immigrants appears as potential explanation. Employment, social protection and re-universalization of healthcare would prevent further deterioration of immigrants' health status.

Association between Integration Policies and Immigrants' Mortality: An Explorative Study across Three European Countries

Background

To integrate immigrants into their societies, European countries have adopted different types of policies, which may influence health through both material and psychosocial determinants. Recent studies have suggested poorer health outcomes for immigrants living in countries with poorly rated integration policies.

Objective

To analyse mortality differences of immigrants from the same country of origin living in countries with distinct integration policy contexts.

Methods

From the mortality dataset collected in the Migrant Ethnic Health Observatory (MEHO) project, we chose the Netherlands (linked data from 1996-2006), France (unlinked; 2005-2007) and Denmark (linked; 1992-2001) as representatives of the inclusive, assimilationist and exclusionist policy models, respectively, based on the Migrant Integration Policy Index. We calculated for each country sex- and age-standardized mortality rates for Turkish-, Moroccan- and local-born populations aged 20-69 years. Poisson regression was used to estimate the mortality rate ratios (MRRs) for cross-country and within-country comparisons. The analyses were further stratified by age group and cause of death.

Results

Compared with their peers in the Netherlands, Turkish-born immigrants had higher all-cause mortality in Denmark (MRR men 1.92; 95% CI 1.74-2.13 and women 2.11; 1.80-2.47) but lower in France (men 0.64; 0.59-0.69 and women 0.58; 0.51-0.67). A similar pattern emerged for Moroccan-born immigrants. The relative differences between immigrants and the local-born population were also largest in Denmark and lowest in France (e.g., Turkish-born men MRR 1.52; 95% CI 1.38-1.67 and 0.62; 0.58-0.66, respectively). These patterns were consistent across all age groups, and more marked for cardiovascular diseases.

Conclusions

Although confounders and data comparability issues (e.g., French cross-sectional data) may affect the findings, this study suggests that different macro-level policy contexts may influence immigrants’ mortality. Comparable mortality registration systems across Europe along with detailed socio-demographic information on immigrants may help to better assess this association.

Prospective register-based study of the impact of immigration on educational inequalities in mortality in Norway

Background

Differences in mortality with regard to socioeconomic status have widened in recent decades in many European countries, including Norway. A rapid upsurge of immigration to Norway has occurred since the 1990s. The article investigates the impact of immigration on educational mortality differences among adults in Norway.

Methods

Two linked register-based data sets are analyzed; the first consists of all registered inhabitants aged 20–69 in Norway January 1, 1993 (2.6 millions), and the second of all registered inhabitants aged 20–69 as of January 1, 2008 (2.8 millions). Deaths 1993–1996 and 2008–2011, respectively, immigrant status, and other background information are available in the data. Mortality is examined by Cox regression analyses and by estimations of age-adjusted deaths per 100,000 personyears.

Results

Both relative and absolute educational inequality in mortality increased from the 1993–1996 period to 2008–2011, but overall mortality levels went down during these years. Immigrants in general, and almost all the analyzed immigrant subcategories, had lower mortality than the native majority. This was due to comparatively low mortality among lower educated immigrants, while mortality among higher educated immigrants was similar to the mortality level of highly educated natives.

Conclusions

The widening of educational inequality in mortality during the 1990s and 2000s in Norway was not due to immigration. Immigration rather contributed to slightly lower overall mortality in the population and a less steep educational gradient in mortality.