Differences in hospitalizations associated with severe COVID-19 disease among foreign- and Swedish-born

Differences in pre-existing health conditions are hypothesized to explain immigrants' excess COVID-19 mortality compared to natives. In this study, we evaluate whether immigrants residing in Sweden before the outbreak were more likely to be hospitalized for conditions associated with severe COVID-19 disease.

A cohort study using population-register data was conducted with follow-up between 1 January 1997 and 31 December 2017. Poisson regression was fitted to estimate incidence rate ratio (RR) and 95% confident intervals (95% CI) for 10 causes of hospitalization.

Compared to Swedish-born individuals, most immigrant groups showed a decreased risk of hospitalization for respiratory chronic conditions, CVD, cancer, chronic liver conditions and neurological problems. All immigrant groups had increased risk of hospitalization for tuberculosis [RR between 88.49 (95% CI 77.21; 101.40) for the Horn of Africa and 1.69 (95% CI 1.11; 2.58) for North America], HIV [RR between 33.23 (95% CI 25.17; 43.88) for the rest of Africa and 1.31 (95% CI 0.93; 1.83) for the Middle East] and, with a few exceptions, also for chronic kidney conditions, diabetes and thalassemia.

Foreign-born individuals-including origins with excess COVID-19 mortality in Sweden-did not show increased risk of hospitalizations for most causes associated with severe COVID-19 disease. However, all groups showed increased risks of hospitalization for tuberculosis and HIV and, with exceptions, for chronic kidney conditions, diabetes and thalassemia. Although studies should determine whether these health conditions explain the observed excess COVID-19 mortality, our study alerts to an increased risk of hospitalization that can be avoidable via treatment or preventive measures.