Effectiveness of azvudine against severe outcomes among hospitalized COVID-19 patients in Xinjiang, China: a single-center, retrospective, matched cohort study.

Background: Since the end of 2022, Azvudine was widely used to treat hospitalized coronavirus disease 2019 (COVID-19) patients in China. However, data on the real-world effectiveness of Azvudine against severe outcomes and post-COVID-19-conditions (PCC) among patients infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variants was limited. This study evaluates the effectiveness of Azvudine in hospitalized COVID-19 patients during a SARS-CoV-2 Omicron BA.5 dominance period.

Methods: From 1 November 2022 to 1 July 2023, an SARS-CoV-2 Omicron BA.5 dominant period, we conducted a single-center retrospective cohort study based on hospitalized patients with laboratory-confirmed SARS-CoV-2 infection from a tertiary hospital in Shihezi, China. Patients treated with Azvudine and usual care were propensity-score matched (PSM) at a 1:1 ratio to a control group in which patients received usual care only, with matching based on covariates such as sex, age, ethnicity, number of preexisting conditions, antibiotic use at admission, and baseline complete blood cell count. The primary outcomes were all-cause death and short-term (60 days) PCC post discharge. The secondary outcomes included the initiation of invasive mechanical ventilation and PCC at long-term post discharge (120 days). Cox proportional hazards (PH) regression models were employed to estimate the hazard ratios (HR) of Azvudine treatment for both all-cause death and invasive mechanical ventilation, and logistic regression models were used to estimate the odds ratios (OR) for short-term and long-term PCC. Subgroup analyses were performed based on a part of the matched covariates.

Results: A total of 2,639 hospitalized patients with SARS-CoV-2 infection were initially identified, and 2,069 ineligible subjects were excluded from analyses. After matching, 297 Azvudine recipients and 297 matched controls were eligible for analyses. The incidence rate of all-cause death was relatively lower in the Azvudine group than in control group (0.007 per person, 95% confidence interval [CI]: 0.001, 0.024 vs 0.128, 95% CI: 0.092, 0.171), and the use of Azvudine was associated with a significantly lower risk of death (HR: 0.049, 95% CI: 0.012, 0.205). Subgroup analyses suggested protection of Azvudine against the risks of all-cause death among men, age over 65, patients without the preexisting conditions, and patients with antibiotics dispensed at admission. Statistical differences were not observed between the Azvudine group and the control group for the risks of invasive mechanical ventilation or short and long-term PCC.

Conclusions: Our findings indicated that Azvudine was associated with lower risk of all-cause death among hospitalized patients with Omicron BA.5 infection in a real-world setting. Further investigation is needed to explore the effectiveness of Azvudine against the PCC after discharge.