Clinical Course and Risk Factors for Mortality of Adult in Patients with COVID-19 in Wuhan, China: A Retrospective Cohort Study

Nowadays 2019 Coronavirus Disease (COVID-19) has become a threat of the word. As of Mar 28, 2020, more than 500 thousand patients have been confirmed as COVID-19 with 23335 deaths. Although the clinical feature of COVID-19 had descried in several previous studies, the risk factors of death and clinical course of COVID-19 including viral shedding has not been established. 

Dr. Cao and his colleges included all 191 inpatients with definite outcome (death or discharged) in Wuhan Jinyintan Hospital and Wuhan Pulmonary Hospital, Which were the only designated hospital in Wuhan as of Jan 31, 2020. The clinical courses of severe COVID-19 were compared between survivors and non-survivors. The median duration of fever was similar between these two groups (12 or 13 days). In survivors, dyspnea would relieve after about 13 days after the occurrence of shortness, while the symptom would last until death in non-survivors. About 45% patients still had cough at discharge. 

The study first document that age, high SOFA score and D-Dimer > 1 ug/ml on admission were independent risk factors of in-hospital death, which could help clinicians identify the cases with poor prognosis at early stage. The lymphocytopnia will recovery from 7-10 days after illness onset in survivors, while severe lymphopenia was observed until death in non-survivors. Dramatic increase of high-sensitivity cardiac troponin I, serum ferritin and IL-6 were observed in non-survivors along with illness deterioration. Lactate dehydrogenase increased for both survivors and non-survivors in the early stage of illness, but decreased from day 13 for survivors. Closely monitoring these markers was needed for severe COVID-19. 

They also reveal that the median duration of viral shedding was 20 days in severe COVID-19, and could prolonged as 37 days. The duration of viral shedding was about 19 days and 24 days for patients with severe status and critical ill status respectively. Although 29 survivors received lopinavir/ritonavir treatment, the median duration was viral shedding was 20 days, and the time from illness onset to receive antiviral treatment was 14 days. It indicates early and adequate antiviral treatment was necessary for COVID-19 pneumonia.  

Some limitation should be noted. Due to excluding cases till in hospital and more severe disease at early stage, the death rate of the cohort could not reflect the mortality of severe COVID-19. Some markers such as serum ferritin and IL-6 may be underestimated in predicting in-hospital death, for not all laboratory tests were done in all patients.