Patterns of COVID-19 related excess mortality in the municipalities of Northern Italy

The Coronavirus Disease 2019 (COVID-19) spatial distribution in Italy is inhomogeneous, because of its ways of spreading from the initial hotspots. The impact of COVID-19 on mortality has been described at the regional level, while less is known about mortality in demographic subgroups within municipalities. We aimed to describe the excess mortality (EM) due to COVID-19 in the three most affected Italian regions, by estimating EM in subgroups defined by gender and age classes within each municipality from February 23 to March 31, 2020. EM varied widely among municipalities even within the same region; it was similar between genders for the ≥75 age group, while in the other age groups it was higher in males. Thus, nearby municipalities may show a different mortality burden despite being under common regional health policies, possibly as a result of policies adopted both at the regional and at the municipality level.