Excess mortality and COVID-19 deaths in Italy: A peak comparison study.

Abstract

During a sanitary crisis, excess mortality measures the number of all-cause deaths, beyond what we would have expected if that crisis had not occurred. The high number of COVID-19 deaths started a debate in Italy with two opposite positions: those convinced that COVID-19 deaths were not by default excess deaths, because many COVID-19 deaths were not correctly registered, with most being attributable to other causes and to the overall crisis conditions; and those who presented the opposite hypothesis. We analyzed the curve of the all-cause excess mortality, during the period of January 5, 2020-October 31, 2022, compared to the curve of the daily confirmed COVID-19 deaths, investigating the association between excess mortality and the recurrence of COVID-19 waves in Italy. We compared the two curves looking for the corresponding highest peaks, and we found that 5 out of the 6 highest peaks (83.3%) of the excess mortality curve have occurred, on average, just a week before the concomitant COVID-19 waves hit their highest peaks of daily deaths (Mean 6.4 days; SD 2.4 days). This temporal correspondence between the moments when the excess mortality peaked and the highest peaks of the COVID-19 deaths, provides further evidence in favor of a positive correlation between COVID-19 deaths and all-cause excess mortality.