Differences in the clinical characteristics of COVID-19 patients who died in hospital during different phases of the pandemic: national data from Italy

Background Epidemiological data obtained during the initial wave of the COVID-19 epidemic showed that persons dying with COVID-19 were typically older men with multiple chronic conditions. No studies have assessed if the characteristics of patients dying with COVID-19 have changed in the second phase of the epidemic, when the initial wave subsided. The aim of the present study was to compare characteristics of patients dying with COVID-19 in Italy in the first 'peak' phase of the epidemic and in its second phase. Methods Medical charts of patients with COVID-19 who died while in hospital in Italy were reviewed to extract information on pre-existing comorbidities, in-hospital complications, and disease trajectories. The course of the epidemic was classified in two 3-month periods: March-May 2020 and June-August 2020. Findings Overall, in the Italian population, 34,191 COVID-19 deaths occurred in March-May 2020 and 1,404 in June-August 2020. Patients dying in March-May were significantly younger (80.1 +/- 10.6 vs. 82.8 +/- 11.1 years, p < 0.001) and less frequently female (41.9% vs. 61.8%, p < 0.001) than those dying in June-August. The medical charts of 3533 patients who died with PCR-confirmed SARS-CoV-2 infection in March-May 2020 (10.3% of all deaths occurring in this period) and 203 patients who died in June-August 2020 (14.5% of all deaths occurring in this period) were analysed. Patients who died in March-May 2020, compared to those who died in June-August 2020, had significantly lower rates of multiple comorbidities (3 or more comorbidities: 61.8% vs 74.5%, p = 0.001) and superinfections (15.2% vs. 52.5%, p < 0.001). Treatment patterns also substantially differed in the two study periods, with patients dying in March-May 2020 being less likely to be treated with steroids (41.7% vs. 69.3%, p < 0.001) and more likely to receive antivirals (59.3% vs. 41.4%, p < 0.001). Survival time also largely differed, with patients dying in March-May 2020 showing a shorter time from symptoms onset to death (mean interval: 15.0 vs. 46.6 days, p < 0.001). The differences observed between the two periods remained significant in a multivariate analysis. Interpretation The clinical characteristics of patients dying with COVID-19 in Italy, their treatment and symptom-to-death survival time have significantly changed overtime. This is probably due to an improved organization and delivery of care and to a better knowledge of disease treatment.