Three possible factors explaining the high case-fatality rate in relation to COVID-19 in Italy

Best Practice Nordic | Maalis 2020 | COVID-19 |

The outbreak of coronavirus disease 2019 (COVID-19) has caused deaths across many countries. However, one country stands out in terms of confirmed cases and a high fatality rate: Italy. With an overall case-fatality rate of 7.2%, Italy has a considerably higher case-fatality rate compared to China at 2.3%. But what are the underlying reasons for this high case-fatality rate? Journal of the American Medical Association Network (JAMA) has proposed three factors that describes the higher rates.1 Definition of fatality rate JAMA Network defines the fatality rate as the: “number of deaths in persons who was tested positive for SARS-CoV-2 divided by the number of SARS-CoV-2 cases.” From March 17th the overall fatality rate of Italians confirmed with COVID-19 was 7.2%, 1625 deaths and 22.512 cases. 1. Italy has an older age distribution The first possible factor explaining the high fatality rate is Italy’s demographic characteristic of the population. Compared with other countries Italy’s proportion of elderly is much higher. In 2019 around 23% of the Italian population was aged 65 years or older. COVID-19 is much more mortal for elderly. Thus, this could in part explain the high case-fatality rate. Comparing with China, the case-fatality rate appears very similar for age groups 0 to 60 years. Nonetheless, the rates are higher for Italian individuals aged 70 or older. Especially the age group of 80 or older and 90 or order. 2. Definition of COVID-19–Related Deaths As a second explanation, JAMA points out a potential overestimation of the case-fatality rate. The Italian statistics of COVID-19 related deaths are not accounting for other comorbidities, such as diabetes, heart diseases or cancer. Instead the COVID-19 related deaths are simply defined as those that occurs in patients tested positive for SARS-CoV-2. In a detailed chart review it was found that among a subsample of...