Methods
This is a single-center retrospective observational study conducted at
Atsugi City Hospital, Kanagawa, Japan. This study was approved by the
ethics committee of this hospital (approval number: R2-07). Data among
adult inpatients (≥20 years old) with COVID-19 treated with SPT from
February 5 to May 31, 2020, were retrospectively reviewed. Throat or
nasal swabs were taken for the reverse transcription polymerase chain
reaction (RT-PCR) test. A diagnosis of COVID-19 was determined when both
clinical symptoms and positive RT-PCR were observed. Day 1 was defined
as the first onset of the symptoms.