All consecutive patients included in this study had a definitive outcome (died, discharged or still hospitalised) within 28 days, with the time period spanning from 24 January 2020 to 10 February 2020. All patients received standard treatment, including antiviral therapy, respiratory support (nasal cannulation, mask oxygenation, high-flow nasal cannula oxygen therapy, non-invasive positive pressure ventilation or invasive mechanical ventilation), symptomatic and supportive treatment and antimicrobial therapy, as appropriate, to prevent or treat secondary infections, which was in accordance with the COVID-19 diagnosis and treatment protocols released by the National Health Commission of the People’s Republic of China [16]. This retrospective project did not interfere with the course of medical management.