To analyze the clinical characteristics of blood coagulation function in patients with COVID-19 and its significance in predicting and prognosis of severe symptoms.

The coagulation function data of COVID-19 patients diagnosed in Wuhan Taikang Tongji Hospital from February to April 2020 were collected and their correlation with the severity and prognosis of COVID-19 patients.

A total of 356 patients who met the criteria were collected. at the time of admission, there were 200 cases of common type, 118 cases of severe type and 38 cases of critical type. At discharge, there were 190 cases of common type, 107 cases of severe type and 59 cases of critical type. The critically ill patients with significantly elevated D-dimer and heparin intervention were defined as heparin group, and the critically ill patients with significantly elevated D-dimer without heparin intervention were defined as non-heparin group. There were 53 cases in heparin group and 41 cases in non-heparin group. The longer the prothrombin time (PT), the higher the D-dimer (DD), the higher the D-dimer (D-dimer) and the lower the platelet count, the higher the probability of diagnosis of severe and critical patients. Age could significantly affect the severity of symptoms (P<0.05, OR=1.054), every 1 increase in age increases the probability of severe illness by 0.054 times. PT can significantly affect the severity of symptoms (P<0.05, OR=1.245), for every 1 increase in PT, the probability of severe illness increases by 0.245 times.

COVID-19 patients with advanced age, basic cardiovascular diseases, prolonged PT and elevated D-dimer are all high risk factors for severe illness and important factors for predicting the prognosis of critically ill patients.