Objectives: to describe trends of overall and intensive care hospitalization for COVID-19 since the beginning of the pandemic in Italy until June 2021, and to compare the results between foreign and Italian population.
Design: retrospective observational study.
Setting and participants: hospital discharges of 28 million people living in Lombardy, Piedmont, Emilia-Romagna (Northern Italy), Toscana and Lazio (Central Italy) occurred between 22.02.2020 and 02.07.2021 in the hospitals located in each considered Region.
Main outcome measures: two weekly outcomes were examined: 1. the overall number of COVID-19 hospitalizations; 2. the number of COVID-19 hospitalizations in intensive care units.
Results: a higher COVID-19 overall and intensive care unit hospitalization was found among the foreign population compared to Italians. The association emerged only after the adjustment for age, and it was consistent among all Regions, though less marked in Lombardy. The association varied across epidemic phases.
Conclusions: the issue of vulnerability of migrants to the risk of severe COVID-19 calls for a diversity-sensitive approach in prevention. The specific country of origin and the prevalence of preventable co-morbidities that are often underestimated in the migrant populations, and related to COVID-19 complications, should be taken into consideration in future analyses.
Keywords: COVID-19; Hospitalisation; Immigrants; Intensive care; Italy.