In this retrospective study, we aimed to evaluate the clinical efficacy and safety of two antiviral drugs on COVID-19 and inpatients with existing complications in the First Affiliated Hospital of Shandong First Medical University. In addition, we also explored a key issue. Is the combined treatment effect of two antiviral drugs, Paxlovid and Azvudine, better than the use of a single drug?

We conducted a single center retrospective cohort study on hospitalized patients with severe acute respiratory syndrome coronavirus type 2 infection who received treatment with nimatevir/ritonavir tablets or azivudine tablets at the First Affiliated Hospital of Shandong First Medical University from December 1，2022 to January 31，2023. In the research of this project, it is necessary to extract, sort out and retrospectively analyze the clinical data of all patients with COVID-19 who have received Nematovir/Ritonavir tablets or Azivudine tablets in the First Affiliated Hospital of Shandong First Medical University (Shandong Qianfoshan Hospital), and respectively identify the relevant epidemiological characteristics of COVID-19 patients, It is planned to use multiple linear regression or logical regression model to explore the relevant factors that affect the drug use efficiency index, safety index and total cost of patients with COVID-19, so as to provide scientific and quantitative evidence support for the drug use mode of the disease, the clinical value of the drug and the rational drug use of patients, and also provide favorable basis for the supervision and decision-making of smart pharmacy of medical institutions.

Inclusion Criteria:

• 1. The patient's admission time is from December 1,2022 to January 31,2023. 2. The patient has used either Paxlovid or azivudine tablets during admission. 3. Age ≥ 18 years old. Exclusion Criteria：
• 1. Patients using other antiviral drugs. 2. Patients with incomplete clinical data.

All inpatients who were treated with nimatevir/ritonavir tablets and azivudine tablets at the First Affiliated Hospital of Shandong First Medical University from December 1,2022 to January 31,2023.