ome, coagulation dysfunction, multiple organ failure, etc.[3, 4]. Therefore, early identification of the severity is very important to the clinical diagnosis of and treatment for COVID-19. Commonly used clinical laboratory coagulation indexes, such as D-dimer (DD), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen (Fg), could sensitively reflect the clotting state of the body.
The aim of the report is to investigate role of the dynamic changes of DD, PT, APTT, TT, and Fg in predicting the severity and prognosis in patients with COVID-19.

2. Materials and Methods

2.1. Source of Patients and Diagnosis Criteria
The information of a to