Real-World Effectiveness of Nirmatrelvir/Ritonavir in Hospitalized Older Adults with Severe Omicron COVID-19: A Retrospective Cohort Study from China

Abstract

Background: The real-world effectiveness of Nirmatrelvir/ritonavir (NMV/RTV) against the SARS-CoV-2 Omicron variant in older patients remains uncertain. We aimed to estimate the effectiveness in older patients aged 80 and above with severe COVID-19. Methods: A retrospective study analyzed 263 COVID-19 patients aged 80 and above, admitted to the Department of Geriatrics at Jinling Hospital, affiliated with Nanjing University, between December 15, 2022, and January 15, 2023. Among them, 136 cases were non-severe, and 127 were severe. The severe cases were further categorized into a survival group (n=74) and a death group (n=53) based on 28-day mortality. Kaplan-Meier survival curves assessed 28-day survival, and Cox regression models identified factors influencing survival. Results: Among the 127 severe cases, the death group had significantly higher rates of stroke history, renal impairment, endotracheal intubation, renal replacement therapy (RRT), bacterial infection, but significantly lower rates of NMV/RTV use and anticoagulation (p<0.05). Kaplan-Meier analysis indicated that NMV/RTV improved 28-day survival in severe older COVID-19 patients. Multivariate Cox regression identified NMV/RTV as a protective factor (adjusted hazard ratio [HR] 0.307, 95% confidence interval [CI] 0.152–0.620, p=0.001), while COPD (adjusted HR 2.993, 95% CI 1.563–5.731, p=0.001), stroke history (adjusted HR 3.871, 95% CI 1.953–7.671, p<0.001), and endotracheal intubation (adjusted HR 5.058, 95% CI 2.809–9.108, p<0.001) were significant risk factors for increased 28-day mortality. Conclusion: NMV/RTV may improve the 28-day survival rate of older patients aged 80 and above with severe COVID-19.