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.