Excess mortality during the COVID-19 outbreak in Italy: a two-stage interrupted time-series analysis. (14th October 2020)

• Record Type: Journal Article
• Authors: Scortichini, Matteo; Schneider dos Santos, Rochelle; De' Donato, Francesca; De Sario, Manuela; Michelozzi, Paola; Davoli, Marina; Masselot, Pierre; Sera, Francesco; Gasparrini, Antonio
• Is Part Of: International journal of epidemiology. Volume 49:Number 6(2020)
• Page Start: 1909
• Page End: 1917
• Publication Date: 2020-10-14
• Subjects: SARS-CoV-2 -- COVID-19 -- epidemic -- Italy -- mortality -- interrupted time series; Epidemiology -- Periodicals; 614.4
• DOI: 10.1093/ije/dyaa169
• Languages: English
• ISSNs: 0300-5771

Abstract

Abstract: Background: Italy was the first country outside China to experience the impact of the COVID-19 pandemic, which resulted in a significant health burden. This study presents an analysis of the excess mortality across the 107 Italian provinces, stratified by sex, age group and period of the outbreak. Methods: The analysis was performed using a two-stage interrupted time-series design using daily mortality data for the period January 2015–May 2020. In the first stage, we performed province-level quasi-Poisson regression models, with smooth functions to define a baseline risk while accounting for trends and weather conditions and to flexibly estimate the variation in excess risk during the outbreak. Estimates were pooled in the second stage using a mixed-effects multivariate meta-analysis. Results: In the period 15 February–15 May 2020, we estimated an excess of 47 490 [95% empirical confidence intervals (eCIs): 43 984 to 50 362] deaths in Italy, corresponding to an increase of 29.5% (95% eCI: 26.8 to 31.9%) from the expected mortality. The analysis indicates a strong geographical pattern, with the majority of excess deaths occurring in northern regions, where few provinces experienced increases up to 800% during the peak in late March. There were differences by sex, age and area both in the overall impact and in its temporal distribution. Conclusion: This study offers a detailed picture of excess mortality during the first months of the COVID-19 pandemic in Italy. The strong geographical and temporal patterns can be related to the implementation of lockdown policies and multiple direct and indirect pathways in mortality risk.