Introduction
Coronavirus disease (COVID-19) is a self-limiting disease in more than 80% of patients, and severe pneumonia occurs in approximately 15% of patients. However, rapid disease transmission turned the COVID-19 outbreak into a pandemic (1-3). The COVID-19 outbreak began and spread worldwide in December 2019 (4, 5), and on January 4, 2021, the World Health Organization reported a total of 83,910,386 COVID-19 cases globally.
Epidemiological estimates suggest that 50% of patients testing positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on nucleic acid testing have no typical symptoms (i.e., fever, cough, or shortness of breath) (6-9). Asymptomatic and presymptomatic viral shedding not only poses a big challenge to infection control but also adds complexity to appropriate clinical decision-making and resource allocation(10, 11). It is noteworthy that the mortality rate varies from country to country, possibly reflecting the differences in how rapidly local health authorities respond to isolate and initiate effective stratification and management strategies for the infected population (12). Hospitalization of all infected persons places too much burden on the healthcare system, but management based only on symptoms may not be appropriate(13). The prediction of asymptomatic, non-severe presymptomatic, and severe presymptomatic COVID-19 in patients could facilitate clinical resource allocation by health authorities, and improve the prognosis of patients. However, at present, there is no method for the risk stratification of asymptomatic and presymptomatic COVID-19 patients.
This study was conducted to comparatively evaluate the clinical characteristics of COVID-19 patients and construct a two-step risk-stratification model based on clinical indicators to distinguish among asymptomatic, severe presymptomatic, and non-severe presymptomatic COVID-19 patients on admission.