COVID-19 mortality among immigrants by duration of residence in Sweden: a population-based cohort study

BACKGROUND

Explanations for the disproportional COVID-19 burden among immigrants relative to host-country natives include differential exposure to the virus and susceptibility due to poor health conditions. Prior to the pandemic, immigrants displayed deteriorating health with duration of residence that may be associated with increased susceptibility over time. The aim of this study was to compare immigrant-native COVID-19 mortality by immigrants' duration of residence to examine the role of differential susceptibility.

METHODS

A population-based cohort study was conducted with individuals between 18 and 100 years old registered in Sweden between 1 January 2015 and 15 June 2022. Cox regression models were run to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Inequalities in COVID-19 mortality between immigrants and the Swedish-born population in the working-age group were concentrated among those of non-Western origins and from Finland with more than 15 years in Sweden, while for those of retirement age, these groups showed higher COVID-19 mortality HRs regardless of duration of residence. Both age groups of immigrants from Africa and the Middle East showed consistently higher COVID-19 mortality HRs. For the working-age population: Africa: HR<15: 2.46, 95%CI: 1.78, 3.38; HR≥15: 1.49, 95%CI: 1.01, 2.19; and from the Middle East: HR<15: 1.20, 95%CI: 0.90, 1.60; HR≥15: 1.65, 95%CI: 1.32, 2.05. For the retirement-age population: Africa: HR<15: 3.94, 95%CI: 2.85, 5.44; HR≥15: 1.66, 95%CI: 1.32, 2.09; Middle East: HR<15: 3.27, 95%CI: 2.70, 3.97; HR≥15: 2.12, 95%CI: 1.91, 2.34.

CONCLUSIONS

Differential exposure, as opposed to differential susceptibility, likely accounted for the higher COVID-19 mortality observed among those origins who were disproportionately affected by the pandemic in Sweden.

Explaining COVID-19 mortality among immigrants in Sweden from a social determinants of health perspective (COVIS): protocol for a national register-based observational study

INTRODUCTION

Adopting a social determinants of health perspective, this project aims to study how disproportionate COVID-19 mortality among immigrants in Sweden is associated with social factors operating through differential exposure to the virus (eg, by being more likely to work in high-exposure occupations) and differential effects of infection arising from socially patterned, pre-existing health conditions, differential healthcare seeking and inequitable healthcare provision.

METHODS AND ANALYSIS

This observational study will use health (eg, hospitalisations, deaths) and sociodemographic information (eg, occupation, income, social benefits) from Swedish national registers linked using unique identity numbers. The study population includes all adults registered in Sweden in the year before the start of the pandemic (2019), as well as individuals who immigrated to Sweden or turned 18 years of age after the start of the pandemic (2020). Our analyses will primarily cover the period from 31 January 2020 to 31 December 2022, with updates depending on the progression of the pandemic. We will evaluate COVID-19 mortality differences between foreign-born and Swedish-born individuals by examining each mechanism (differential exposure and effects) separately, while considering potential effect modification by country of birth and socioeconomic factors. Planned statistical modelling techniques include mediation analyses, multilevel models, Poisson regression and event history analyses.

ETHICS AND DISSEMINATION

This project has been granted all necessary ethical permissions from the Swedish Ethical Review Authority (Dnr 2022-0048-01) for accessing and analysing deidentified data. The final outputs will primarily be disseminated as scientific articles published in open-access peer-reviewed international journals, as well as press releases and policy briefs.

Spousal order of migration, gender, and hospitalization among immigrants in Denmark

Background: Certain migration contexts that may help clarify immigrants' health needs are understudied, including the order in which married individuals migrate. Research shows that men, who are healthier than women across most populations, often migrate to a host country before women. Using Danish register data, we investigate descriptive patterns in the order that married men and women arrive in Denmark, as well as whether migration order is related to overnight hospitalizations. Methods: The study base includes married immigrants who lived in Denmark between January 1, 1980 and December 31, 2014 (N = 13,680). We use event history models to examine the influence of spousal migration order on hospitalizations. Results: The order that married individuals arrive in Denmark is indeed highly gendered, with men tending to arrive first, and varies by country of origin. Risk of hospitalization after age 50 does not depend on whether an individual migrated before, after, or at the same time as their spouse among either men or women. However, among those aged 18+, men migrating before their wives are more likely to experience hospitalizations within the first 5 years of arrival. Conclusions: These findings provide the first key insights about gendered migration patterns in Denmark. Although spousal order of migration is not related to overnight hospitalization among women, our findings provide preliminary evidence that men age 18+ who are first to arrive experience more hospitalization events in the following 5 years. Future research should explore additional outcomes and whether other gendered migration contexts are related to immigrants' health.

COVID-19 mortality across occupations and secondary risks for elderly individuals in the household: A population register-based study

OBJECTIVES

This is the first population-level study to examine inequalities in COVID-19 mortality according to working-age individuals' occupations and the indirect occupational effects on COVID-19 mortality of older individuals who live with them.

METHODS

We used early-release data for the entire population of Sweden of all recorded COVID-19 deaths from 12 March 2020 to 23 February 2021, which we linked to administrative registers and occupational measures. Cox proportional hazard models assessed relative risks of COVID-19 mortality for the working-aged population registered in an occupation in December 2018 and the older population who lived with them.

RESULTS

Among working aged-adults, taxi/bus drivers had the highest relative risk of COVID-19 mortality: over four times that of skilled workers in IT, economics, or administration when adjusted only for basic demographic characteristics. After adjusting for socioeconomic factors (education, income and country of birth), there are no occupational groups with clearly elevated (statistically significant) COVID-19 mortality. Neither a measure of exposure within occupations nor the share that generally can work from home were related to working-aged adults' risk of COVID-19 mortality. Instead of occupational factors, traditional socioeconomic risk factors best explained variation in COVID-19 mortality. Elderly individuals, however, faced higher COVID-19 mortality risk both when living with a delivery or postal worker or worker(s) in occupations that generally work from home less, even when their socioeconomic factors are taken into account.

CONCLUSIONS

Inequalities in COVID-19 mortality of working-aged adults were mostly based on traditional risk factors and not on occupational divisions or characteristics in Sweden. However, older individuals living with those who likely cannot work from home or work in delivery or postal services were a vulnerable group.

The Fertility of Immigrants From Low-Fertility Settings: Adaptation in the Quantum and Tempo of Childbearing?

Immigrant women who have lived longer in a destination often have relatively low levels of fertility, which is sometimes taken as evidence of the adaptation of behavior. This evidence is almost exclusively based on studies of immigrants from high-fertility settings, while the fertility of immigrants from low-fertility settings has been largely overlooked. Research has also rarely studied the fertility of immigrants who migrated as children, despite the methodological advantages of applying such an approach. This study focuses on women who grew up in Sweden with a migration background from low-fertility origins. We expect that Sweden's welfare regime makes it easier for women to combine childbearing and working life, regardless of migration background, thereby facilitating an adaptation of fertility behavior toward that prevailing in Sweden. We find evidence of adaptation in terms of birth timing for at least half of the country-origin groups that we study, but very little evidence of adaptation in terms of completed fertility. Further, we find that, in comparison with ancestral Swedes, completed fertility differentials are larger for second-generation individuals than for immigrants who arrived during childhood. This is evidence against the notion of "straight-line" adaptation for immigrants and the children of immigrants who are born in Sweden.

Intermarriage and COVID-19 mortality among immigrants. A population-based cohort study from Sweden

OBJECTIVES

To evaluate the role of language proficiency and institutional awareness in explaining excess COVID-19 mortality among immigrants.

DESIGN

Cohort study with follow-up between 12 March 2020 and 23 February 2021.

SETTING

Swedish register-based study on all residents in Sweden.

PARTICIPANTS

3 963 356 Swedish residents in co-residential unions who were 30 years of age or older and alive on 12 March 2020 and living in Sweden in December 2019.

OUTCOME MEASURES

Cox regression models were conducted to assess the association between different constellations of immigrant-native couples (proxy for language proficiency and institutional awareness) and COVID-19 mortality and all other causes of deaths (2019 and 2020). Models were adjusted for relevant confounders.

RESULTS

Compared with Swedish-Swedish couples (1.18 deaths per thousand person-years), both immigrants partnered with another immigrant and a native showed excess mortality for COVID-19 (HR 1.43; 95% CI 1.29 to 1.58 and HR 1.24; 95% CI 1.10 to 1.40, respectively), which translates to 1.37 and 1.28 deaths per thousand person-years. Moreover, similar results are found for natives partnered with an immigrant (HR 1.15; 95% CI 1.02 to 1.29), which translates to 1.29 deaths per thousand person-years. Further analysis shows that immigrants from both high-income and low-income and middle-income countries (LMIC) experience excess mortality also when partnered with a Swede. However, having a Swedish-born partner is only partially protective against COVID-19 mortality among immigrants from LMIC origins.

CONCLUSIONS

Language barriers and/or poor institutional awareness are not major drivers for the excess mortality from COVID-19 among immigrants. Rather, our study provides suggestive evidence that excess mortality among immigrants is explained by differential exposure to the virus.

Correction to: Fertility Intentions Within a 3-Year Time Frame: a Comparison Between Migrant and Native Italian Women

A Correction to this paper has been published: 10.1007/s12134-020-00800-2

Unintended health consequences of Swedish parental leave policy (ParLeHealth): protocol for a quasi-experimental study

INTRODUCTION

Sweden has long been praised for a generous parental leave policy oriented towards facilitating a gender-equitable approach to work and parenting. Yet certain aspects of Swedish parental leave could also be responsible for the maintenance of (or even the increase in) health inequalities. Using a 'Health in All Policies' lens, this research project aims to assess the unintended health consequences of various components of Sweden's parental leave policy, including eligibility for and uptake of earnings based benefits.

METHODS AND ANALYSIS

We will use individual-level data from multiple Swedish registers. Sociodemographic information, including parental leave use, will be retrieved from the total population register, Longitudinal Integration Database for Health Insurance and Labour Market Studies and Social Insurance Agency registers. Health information for parents and children will be retrieved from the patient, prescribed drug, cause of death, medical birth and children's health registers. We will evaluate parents' mental, mothers' reproductive and children's general health outcomes in relation to several policy reforms aiming to protect parental leave benefits in short birth spacing (the speed premium) and to promote father's uptake (the father's quota) and sharing of parental leave days (the double days reform). We will also examine effects of increases in basic parental leave benefit levels. Using quasi-experimental designs, we will compare health outcomes across these reforms and eligibility thresholds with interrupted time series, difference-in-difference and regression discontinuity approaches to reduce the risk of health selection and assess causality in the link between parental leave use and health.

ETHICS AND DISSEMINATION

This project has been granted all necessary ethical permissions from the Stockholm Regional Ethical Review Board (Dnr 2019-04913) for accessing and analysing deidentified data. The final outputs will primarily be disseminated as scientific articles published in open-access, high-impact peer-reviewed international journals, as well as press releases and policy briefs.

Preterm disparities between foreign and Swedish born mothers depend on the method used to estimate gestational age. A Swedish population-based register study

This study aims to examine whether disparities in gestational age outcomes between foreign and Swedish-born mothers are contingent on the measure used to estimate gestational age and, if so, to identify which maternal factors are associated with the discrepancy. Using population register data, we studied all singleton live births in Sweden from 1992–2012 (n = 1,317,265). Multinomial logistic regression was performed to compare gestational age outcomes classified into very (<32 weeks) and late preterm (32–36 weeks), term and post-term derived from the last menstrual period (LMP) and ultrasound estimates in foreign- and Swedish-born women. Compared to Swedish-born women, foreign-born women had similar odds of very preterm birth (OR: 0.98 [95% CI: 0.98, 1.01]) and lower odds of moderately preterm birth (OR: 0.95 [95% CI: 0.92, 0.98]) based on ultrasound, while higher risks based on LMP (respectively, OR: 1.10 [95% CI: 1.07, 1.14] and 1.09 [95% CI: 1.06, 1.13]). Conclusions on disparities in gestational age-related outcomes by mother’s country of origin depend on the method used to estimate gestational age. Except for very preterm, foreign-born women had a health advantage when gestational age is based on ultrasound, but a health disadvantage when based on LMP. Studies assessing disparities in very preterm birth by migration status are not affected by the estimation method but caution should be taken when interpreting disparities in moderately preterm and preterm birth rates.

How Assad changed population growth in Sweden and Norway: Syrian refugees' impact on Nordic national and municipal demography

In an increasingly interconnected world, the demographic effects of wars are not confined only to war zones and neighbouring areas; wars and conflicts may also change populations far away. Without the war in Syria under President Assad and the associated mass exodus of Syrian refugees, the population trends in distant countries like Sweden and Norway over the last few years would have been different. We create hypothetical scenarios of the population developments in Sweden and Norway without a war in Syria from 2011 onwards, where excess immigration due to the war and associated excess births are removed. The results indicate that population growth in 2016 would have been roughly 36% lower in Sweden and 26% lower in Norway without the Syrian war. The number of births in 2017 would have been about 3% lower in Sweden and 1% lower in Norway. One in ten municipalities would have had a population decline in 2016 instead of a population increase, and the largest immigrant group in Sweden by January 2019 would still be of Finnish origin.

Residential context and COVID-19 mortality among adults aged 70 years and older in Stockholm: a population-based, observational study using individual-level data

BACKGROUND

Housing characteristics and neighbourhood context are considered risk factors for COVID-19 mortality among older adults. The aim of this study was to investigate how individual-level housing and neighbourhood characteristics are associated with COVID-19 mortality in older adults.

METHODS

For this population-based, observational study, we used data from the cause-of-death register held by the Swedish National Board of Health and Welfare to identify recorded COVID-19 mortality and mortality from other causes among individuals (aged ≥70 years) in Stockholm county, Sweden, between March 12 and May 8, 2020. This information was linked to population-register data from December, 2019, including socioeconomic, demographic, and residential characteristics. We ran Cox proportional hazards regressions for the risk of dying from COVID-19 and from all other causes. The independent variables were area (m2) per individual in the household, the age structure of the household, type of housing, confirmed cases of COVID-19 in the borough, and neighbourhood population density. All models were adjusted for individual age, sex, country of birth, income, and education.

FINDINGS

Of 279 961 individuals identified to be aged 70 years or older on March 12, 2020, and residing in Stockholm in December, 2019, 274 712 met the eligibility criteria and were included in the study population. Between March 12 and May 8, 2020, 3386 deaths occurred, of which 1301 were reported as COVID-19 deaths. In fully adjusted models, household and neighbourhood characteristics were independently associated with COVID-19 mortality among older adults. Compared with living in a household with individuals aged 66 years or older, living with someone of working age (<66 years) was associated with increased COVID-19 mortality (hazard ratio 1·6; 95% CI 1·3-2·0). Living in a care home was associated with an increased risk of COVID-19 mortality (4·1; 3·5-4·9) compared with living in independent housing. Living in neighbourhoods with the highest population density (≥5000 individuals per km2) was associated with higher COVID-19 mortality (1·7; 1·1-2·4) compared with living in the least densely populated neighbourhoods (0 to <150 individuals per km2).

INTERPRETATION

Close exposure to working-age household members and neighbours is associated with increased COVID-19 mortality among older adults. Similarly, living in a care home is associated with increased mortality, potentially through exposure to visitors and care workers, but also due to poor underlying health among care-home residents. These factors should be considered when developing strategies to protect this group.

FUNDING

Swedish Research Council for Health, Working Life and Welfare (FORTE), Swedish Foundation for Humanities and Social Sciences.

Over-coverage in population registers leads to bias in demographic estimates

Estimating the number of individuals living in a country is an essential task for demographers. This study assesses the potential bias in estimating the size of different migrant populations due to over-coverage in population registers. Over-coverage-individuals registered but not living in a country-is an increasingly pressing phenomenon; however, there is no common understanding of how to deal with over-coverage in demographic research. This study examines different approaches to and improvements in over-coverage estimation using Swedish total population register data. We assess over-coverage levels across migrant groups, test how estimates of age-specific death and fertility rates are affected when adjusting for over-coverage, and examine whether over-coverage can explain part of the healthy migrant paradox. Our results confirm the existence of over-coverage and we find substantial changes in mortality and fertility rates, when adjusted, for people of migrating age. Accounting for over-coverage is particularly important for correctly estimating migrant fertility.

Sex differences in mortality in migrants and the Swedish-born population: Is there a double survival advantage for immigrant women?

Objectives

In the present study, we examine whether the relationships between country of origin or reason for migration and mortality differ between men and women.

Methods

We apply hazard regression models on high-quality Swedish register data with nationwide coverage.

Results

Relative to their Swedish counterparts, migrants from Nordic and East European (EU) countries and former Yugoslavia have higher mortality. This excess mortality among migrants relative to Swedes is more pronounced in men than in women. Migrants from Western and Southern European countries; Iran, Iraq, and Turkey; Central and South America; and Asia, have lower mortality than Swedes, and the size of the mortality reduction is similar in both sexes. The predictive effects of the reason for migration for mortality are also similar in migrant men and women.

Conclusions

This study provides little support for the hypothesis of a double survival advantage among immigrant women in Sweden. However, it does show that the excess mortality in migrants from Nordic and EU countries and former Yugoslavia relative to the Swedish-born population is more pronounced in men than in women.

Electronic supplementary material

The online version of this article (10.1007/s00038-019-01208-1) contains supplementary material, which is available to authorized users.

Changes in sex ratio at birth among immigrant groups in Sweden

What happens when citizens from societies with strong son preference culture migrate to countries in which preference for having a child of each sex prevails? Using data from Swedish population registers, we investigate the sex ratio at birth by parity and the sex composition of previous children in Sweden. Our results showed that women with Chinese, Korean, and Indian background had a substantially elevated sex ratio at the third parity if previous children were both girls. Strikingly, this skewed ratio became less pronounced after 2000, suggesting a shift for a more neutral sex preference for children among these groups in the new century.

Being a refugee or having a refugee status? Birthweight and gestational age outcomes among offspring of immigrant mothers in Sweden

Aims: to evaluate whether the information on refugee status based on the residence permit is a useful source of information for perinatal health surveillance. Methods: Using the Swedish population registers (1997-2012), we use multinomial regression models to assess the associations between migration status (refugee and non-refugee) and birth outcomes derived from birthweight and gestational age: low birthweight (LBW) (<2500 g), macrosomia (≥4000 g); preterm: (<37 w) and post-term (≥42 w). The Swedish-born population was used as a reference group. Results: Compared to the Swedish-born population, an increased OR (odds ratio) of LBW and post-term was found among migrants with and without refugee status (respectively: OR for refugees: 1.47 [95% CI: 1.33-1.63] and non-refugees:1.27 [95% CI: 1.18-1.38], for refugees: 1.41 [95% CI: 1.35-1.49] and non-refugees:1.04 [95% CI: 1.00-1.08]) with statistically significant differences between these two migrant categories. However, when looking at specific regions of origin, few regions show differences by refugee status. Compared to Swedes, lower or equal ORs of preterm and macrosomia are observed regardless of migratory status. Conclusions: Small or no differences were observed in birth outcomes among offspring of women coming from the same origin with different migratory status, compared to their Swedish counterparts. This suggests that information on migration status is not a relevant piece of information to identify immigrant women at higher risk of experiencing adverse reproductive outcomes. Our results however might be explained by the large proportion of women coming to Sweden for family reunification who are classified as non-refugee migrants.

Use It or Save It? Migration Background and Parental Leave Uptake in Sweden

Sweden is a welfare state with a family policy that strongly emphasizes equality without distinction by place of birth or gender. In this study, we investigate the differences in uptake of parental leave between native and immigrant mothers, and the connection to labour-market attachment. Sweden represents a unique case study, not only because of the strong effort to combine work and family for all women and men, the high level of fertility and the large presence of immigrants in the country; it also enables a detailed and sophisticated analysis based on the high-quality data derived from its population registers. We find that immigrant mothers use more parental leave benefit the first year after their child's birth, but then fewer in the second year compared with native mothers. The differences diminish when labour-market activity is controlled for. Additionally, after a time in Sweden, immigrant mothers use leave more similarly to how native mothers do.

Transradial access and radiation exposure in diagnostic and interventional coronary procedures

BACKGROUND

Although transradial access (TRA) is being increasingly used in interventional cardiology, there are concerns about a possible increase in radiation exposure (RE) as compared to transfemoral access (TFA).

METHODS

In this retrospective study, we aimed to compare RE during coronary angiography and percutaneous coronary intervention (PCI) according to the vascular access route (TRA vs TFA). We included all procedures performed in our laboratory, in which RE data (dose area product, cGy•cm²) were available, from May 2009 to May 2013. Both multiple linear regression analysis and propensity score matching were performed in order to compare RE between TRA and TFA after adjusting for clinical and procedural confounders.

RESULTS

DAP values were available for 1396 procedures; TRA rate was 82.6%. TRA patients were younger, less frequently female, and had higher body mass index as compared to TFA patients; the rates of PCI, ad hoc PCI, bypass angiography, thrombus aspiration, and primary angioplasty, as well as the number of stents implanted, fluoroscopy time, and contrast dose were significantly higher in TFA. Median DAP value was significantly higher in TFA than in TRA (9670 cGy•cm² vs 7635 cGy•cm²; P<.01). After adjusting for clinical and procedural confounders, vascular access was not found to be an independent predictor of RE at multiple regression analysis; this was also confirmed by stratified comparison of DAP values by quintiles of propensity score.

CONCLUSION

After adjusting for clinical and procedural confounders, TRA was not found to be associated with increased RE as compared to TFA in an experienced TRA center.

Early impairment of myocardial function in young patients with beta-thalassemia major

BACKGROUND AND OBJECTIVE

One of the chief causes of death in patients with beta-thalassemia major (TM) remains heart failure due to iron overload. We investigated possible differences in myocardial function between a population of young asymptomatic patients with TM and healthy controls all of whom underwent an echocardiographic study, including tissue Doppler (TDI) and strain imaging (SI) analysis and cardiac magnetic resonance imaging (MRI).

METHODS

30 young asymptomatic patients with TM (16 taking deferoxamine and 14 taking deferiprone) and 30 healthy subjects underwent a cardiac MRI with T2* technique and an echocardiographic evaluation including systolic myocardial velocities (Sm), early (Em) and late (Am) diastolic velocities and systolic strain (S) at the level of basal segments of the lateral left ventricle (LV), interventricular septum (Septal) and lateral right ventricle (RV) wall. The differences in T2* values and echocardiographic parameters were also compared in patients with TM subgrouped according to iron chelation therapy.

RESULTS

The following TDI and SI measures were lower in patients than in controls: LV-Sm (P < 0.05), S-LV (P < 0.001), Septal-Sm (P < 0.05), Septal-Em (P < 0.001), S-Septal (P < 0.001), RV-Sm (P < 0.001), RV-Em (P < 0.001), RV-Em/Am (P < 0.05) and S-RV (P < 0.05). Myocardial function was better in the patients receiving deferiprone than those receiving deferoxamine. T2* values were higher in controls than in patients with TM and in those treated with deferiprone than those treated with deferoxamine. MRI data well correlated with SI parameters.

CONCLUSIONS

Study underlines that, even in a population of young, asymptomatic and well-chelated patients with TM, there is an impairment of myocardial function and that this condition could be easily detected by more advanced ultrasound techniques such as TDI and SI. The better indices of myocardial function in patients treated with deferiprone clearly needs confirmation from larger prospective studies.