Neighbourhood immigrant density and COVID-19 infection and hospitalisation among healthcare workers in Sweden: a register-based observational study.

Introduction: We investigated whether living in immigrant-dominated neighbourhoods constituted a risk factor for COVID-19 infection and hospitalisation among healthcare workers (HCWs) in Sweden, and if so, whether such exposure exacerbated the risk of COVID-19 among immigrant HCWs. Methods: We used population-based register data from HCWs aged 20-62 years (N=86 187) resident in 14 Swedish municipalities (3 of which are Sweden's largest metropolitan cities) on 1 January 2020. Residential neighbourhoods of the HCWs were categorised into three groups: Swedish-dominated, mixed and immigrant-dominated. Multilevel mixed-effects survival regression was used for the association analyses, with control for relevant confounding variables. The results are reported as HRs, with 95% CIs. Results: From 1 January 2020 to 30 September 2022, we recorded 39 746 COVID-19 infections and 860 COVID-19-related hospitalisations. Except during the first wave of the pandemic, living in immigrant-dominated (adjusted HR 0.98; 95% CI 0.94 to 1.01) or mixed (adjusted HR 1.02; 95% CI 0.99 to 1.05) neighbourhoods was not associated with COVID-19 infection, but living in these areas was associated with an increased risk of having COVID-19-related hospitalisation throughout the study period. Immigrant HCWs, regardless of their neighbourhood of residence, had approximately 2-fold higher risk of being hospitalised for COVID-19 than non-immigrant HCWs living in Swedish-dominated neighbourhoods. Conclusions: Among HCWs in Sweden, neighbourhood immigrant density constituted a risk factor for COVID-19-related hospitalisation. However, immigrant HCWs had an elevated risk of COVID-19-related hospitalisation regardless of where they lived.