BACKGROUND: The current coronavirus disease 2019 (COVID-19) is a public health emergency . In this study, we aimed to evaluate the risk factors for mortality in severe and critical COVID-19 patients .
METHODS: We performed a retrospective study of patients diagnosed with severe and critical COVID-19 from four hospitals in Wuhan, China, by evaluating the clinical characteristics and laboratory results, and using Cox proportional hazards model to assess the risk factors involved in disease progression .
RESULTS: In total , 446 patients with COVID-19 were enrolled . The study indicated a high mortality rate (20.2 %) in severe and critical COVID-19 patients . At the time of admission, all patients required oxygen therapy, and 52 (12 %) required invasive mechanical ventilation, of which 50 (96 %) died . The univariate Cox proportional hazards model showed a white blood cell count of more than 10 × 109/L (HR 3.993,95% CI 2.469 to 6.459) that correlated with an increased mortality rate . The multivariable Cox proportional hazards model demonstrated that older age (HR 1.066 , 95% CI 1.043 to 1.089) and higher white blood cell count (HR 1.135 , 95% CI 1.080 to 1.192) were independent risk factors for determining COVID-19 associated mortality .
CONCLUSIONS: COVID-19 is associated with a significant risk of morbidity and mortality in the population . Older age and higher white blood cell count were found to be independent risk factors for mortality.