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

Abstract

ObjectivesTo evaluate the role of language proficiency and institutional awareness in explaining excess COVID-19 mortality among immigrants.DesignCohort study with follow-up between 12 March 2020 and 23 February 2021.SettingSwedish register-based study on all residents in Sweden.Participants3 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 measuresCox 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.ResultsCompared 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.ConclusionsLanguage 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.

Understanding the excess COVID-19 burden among immigrants in Norway

“…The differences between immigrant–immigrant couple and other couples were higher in Norway than previously shown in Sweden, 21 which could indicate that factors related to language barriers and poor institutional awareness might be of higher importance in a setting with low infection pressure (Norway) than a high infection pressure setting (Sweden).…”

“… 8 , 11 Genetic susceptibility to COVID-19 and a severe course of the disease among groups of immigrants have also been proposed, but so far without sufficient empirical support. 20 , 21 …”

“…A Swedish study assessed the role of language barriers and poor institutional awareness in explaining COVID-19 mortality among immigrants by examining immigrants partnered with Swedes. 21 A study design comparing rates of COVID-19 among immigrants who are married to a native and immigrants married to another immigrant is useful to disentangle some of the mechanisms possibly related to higher risk and to assess the relative importance of exposure, underlying risk and barriers. Intermarriage between immigrants and natives is both a proxy and a facilitator of integration.…”

Excess mortality and COVID-19 in Sweden in 2020: A demographic account

“…In addition, our aggregated data did not allow us to examine socioeconomic differences in outcomes, or differences between the native and the immigrant population (cf. Drefahl et al, 2020;Brandén et al, 2020;Rostila et al, 2021;Aradhya et al, 2021). COVID-19 will continue to have an impact on different aspects of Sweden's demographic dynamics over the next few years.…”

“…Several studies conducted in Sweden have examined patterns of COVID-19related mortality based on individual-level data on observed deaths and causes of deaths during the early months of 2020. These studies found that mortality increased, most notably among socioeconomically disadvantaged groups (Drefahl et al, 2020), people living in crowded and multigenerational households (Brandén et al, 2020) and migrants (Aradhya et al, 2021;Rostila et al, 2021). Similar studies on mortality among foreign-born populations have been conducted in Norway (Indseth et al, 2020) and Belgium (Vanthomme et al, 2021).…”