Patient selection
This study was approved by the institutional ethics board of the Henan
Provincial People’s Hospital (ethics approval No: 2020[71]). The
Henan Provincial People’s Hospital was assigned responsibility for the
treatments of patients with severe COVID-19. We conducted an exploratory
study of all the 52 patients with COVID-19 admitted to the hospital from
January 10 to March 30, 2020. The diagnosis of COVID-19 was based on the
China National Health Commission (NHC) Guidelines for the Diagnosis and
Treatment of COVID-19. Confirmed cases had radiologic evidence of
pneumonia or infiltrate on chest CT. The methodology of RT-PCR used has
been previously reported (Wang et al., 2020).