[Impact of the SARS-CoV-2 epidemic on the immigrant population by urbanisation degree in five Italian Regions (Piedmont, Emilia-Romagna, Tuscany, Lazio, and Sicily)].

Background: according to the literature, socially disadvantaged strata of the population, including immigrants, have been more vulnerable to the risk of SARS-CoV-2 infection due to greater exposure and less opportunity to protect themselves, and to COVID-19 complications due to metabolic and clinical risk factors as well as to healthcare access barriers. Two Italian projects - coordinated by the Italian National Institute for Health, Migration and Poverty and the Italian National Centre for Disease Prevention and Control - set up an epidemiological surveillance to monitor the temporal trends of the SARS-CoV-2 pandemic in five Italian regions using validated indicators.

Objectives: to identify differences between Italians and immigrants in terms of the epidemic evolution and its health consequences, and to investigate possible differences by urbanisation degree and region of residence.

Design: cross sectional study.

Setting and participants: resident population in five Italian regions: Piedmont, Emilia-Romagna, Tuscany, Lazio, and Sicily.

Main outcomes measures: frequencies of positive tests, routine hospitalisations, and deaths related to COVID-19 were collected, with respect to the period between 22.02.2020 and 31.01.2021. Data were aggregated by week, region, degree of urbanisation, gender, age (5-year classes), and citizenship (Italian/foreigner). Crude and standardised rates of the outcomes considered were calculated, stratified by gender, citizenship, region, and aggregated by pandemic macro-period.

Results: the study population counts approximately about 23 million residents as of 01.01.2020 (9.4% immigrants). During the period of interest, 1,542,458 cases of infection were recorded, whereas hospitalisations amounted to 175,979, and deaths to 44,867. Lower crude rates of hospitalisations and deaths were observed among immigrants compared to Italians. The age-standardised hospitalisation rates, on the other hand, showed an opposite trend and were significantly higher among immigrants, due to the excess observed in urban areas, especially in periods of epidemic peak, both for males (weekly mean standardised rate: 34.6 per 1,000 of foreign residents vs 24.3 of Italians over the period October 2020-January 2021) and females (23.2 vs 15.1 over the period February-April 2021). These differences seem to be more pronounced in the central regions and tend to disappear for residents in scarcely populated areas. Standardised mortality rates were higher among immigrants, both men and women, from October 2020 and more markedly in February-April 2021 among men.

Conclusions: the impact of COVID-19 was stronger among immigrants in relation to hospitalisation, especially during epidemic peak periods and in some regions. The difference in the impact on mortality was smaller. There is some heterogeneity among regions and urban areas that is worth considering in the planning of interventions and integration policies.