This study investigated the case fatality rate (CFR) among confirmed COVID-19 cases (N=22,512) in Italy, using Italian National Institute of Health surveillance data up to March 17, 2020.
- The overall fatality rate of persons with confirmed COVID-19 in the Italian population, based on data up to March 17, was 7.2% (1625 deaths/22,512 cases). This was substantially higher than the CFR in China, which was 2.3% (1,023/44,672; 2.3%). The largest age differences between the two countries were observed for those aged 70-79 (CFR 12.8% versus 8.0%) and ≥80 years (CFR 20.2% versus 14.8%). CFRs between the two countries were similar for all other age groups.
- The higher CFR in Italy compared with China is likely related to population and testing characteristics. First, the overall age distribution in Italy is higher than in most countries. Individuals ≥70 years represent 37.6% of cases in Italy versus 11.9% in China. Second, case-fatality statistics in Italy are based on defining COVID-19-related deaths as those occurring in patients who test positive for SARS-CoV-2 via RT-PCR, independently from preexisting diseases that may have caused death. This may have led to overestimation of the CFR. Finally, Italy prioritized testing for patients with more severe clinical symptoms who were suspected of having COVID-19 and required hospitalization and limited testing for asymptomatic people of for those with limited, mild symptoms. This may have resulted in a high proportion of positive results and an apparent increase in the CFR.
- There is no standardized definition for COVID-19-related deaths, which may influence country-specific CFRs and comparisons made among countries.