Patients, setting and human ethical approvals
This retrospective observational study, conducted at the Shanghai
Geriatric Medical Center (Meilong Branch of Zhongshan Hospital, Fudan
University), examined individuals with COVID-19 who were hospitalized
from 26th April to 30th June 2022.
The Shanghai Geriatric Medical Center is a specialized medical facility
that admits patients with COVID-19 in Shanghai for treatment. The
omicron sublineage BA.2.2 was the primary cause of COVID-19 cases
reported in Shanghai during this time frame[16].
Patients admitted for SARS-CoV-2
burden rebound were excluded if they had one RT-PCR test during their
hospitalization and the result is negative, a severe COVID-19 diagnosis
upon hospitalization, or insufficient information in the electronic
medical record. The patient’s infection severity was categorized based
on the Diagnosis and Treatment Guideline for COVID-19 (Trial Version 9)
issued by the China National Health
Commission[12]. Mild COVID-19 refer to individuals
experiencing one or multiple mild symptoms such as pyrexia, tussis,
pharyngitis, asthenia, myalgia, anosmia and no concomitant pneumonia.
Patients with moderate COVID-19 exhibit symptoms similar to those with
mild disease, but they also show radiologic signs of pneumonia. The
high-risk group for severe COVID-19 includes individuals aged 60 years
or older who have a medical history of hypertension, cardiovascular
diseases, cerebral infarction, chronic liver or kidney diseases,
cancers, smoking, or obesity[13-15]. This analysis
only included individuals who were diagnosed with mild or moderate cases
of COVID-19 and were deemed to be at a high risk of developing severe
illnesses. Patients were excluded if they had contraindications to
nirmatrelvir-ritonavir, severe renal impairment (estimated glomerular
filtration rate [eGFR] <30 mL/min per 1.73 m², undergoing
dialysis, or had undergone renal transplantation), or severe liver
impairment (cirrhosis, hepatocellular carcinoma, or had undergone liver
transplantation).
This study adhered to STROBE guidelines and received approval from the
ethics committees of Zhongshan Hospital, Fudan University (approval
number B2022-470R). Due to the exceptional circumstances of the COVID-19
outbreak, this retrospective study utilizing de-identified information
did not necessitate individual patient-informed consent.