Objectives: to assess the temporal variation in excess total mortality and the portion of excess explained by COVID-19 deaths by geographical area, gender, and age during the COVID-19 epidemic.
Design: descriptive analysis of temporal variations of total excess deaths and COVID-19 deaths in the phase 1 and phase 2 of the epidemic in Italy.
Setting and participants: 12 Northern cities and 20 Central-Southern cities from December 2019 to June 2020: daily mortality from the National Surveillance System of Daily Mortality (SiSMG) and COVID-19 deaths from the integrated COVID-19 surveillance system.
Main outcome measures: total mortality excess and COVID-19 deaths, defined as deaths in microbiologically confirmed cases of SARS-CoV-2, by gender and age groups.
Results: the largest excess mortality was observed in the North and during the first phase of the epidemic. The portion of excess mortality explained by COVID-19 decreases with age, decreasing to 51% among the very old (>=85 years). In phase 2 (until June 2020), the impact was more contained and totally attributable to COVID-19 deaths and this suggests an effectiveness of social distancing measures.
Conclusions: mortality surveillance is a sensible information basis for the monitoring of health impact of the different phases of the epidemic and supporting decision making at the local and national level on containment measures to put in place in coming months.
Keywords: excess mortality; surveillance system; COVID-19-related deaths; demographic factors.